OV0000 a unique grid square at Beast Cliff

Text © Copyright Peter Standing, September 2006
Images are under a separate Creative Commons Licence.

OV0000 – a unique grid square at Beast Cliff, North Yorkshire

Why OV0000 is so remarkable

OV0000 at Beast Cliff in North Yorkshire is the sole land representative of the OV 100km national grid square or myriad. It is also the only land representative of the much larger 500km grid square (or pentad) which is known by its prefix letter O. The remaining areas of both the OV myriad and the O pentad lie in the North Sea.

As a geograph square, OV0000 only just qualifies with around 10 square metres of boulders above the high tide mark but there is an extensive boulder foreshore above the low tide level. The National Grid Reference OV000000 (or zero point) marks the intersection of the four myriads OV, TA, SE and NZ. Each of these has a different first letter because each belongs to a different pentad. OV000000 is the only point in the UK where four such 500 kilometre squares intersect as can be seen from the OS website map below. With all zero points, circumnavigation prompts a GPS to jump wildly from one myriad to another. OV0000 is the only geograph square where it is possible to photograph an entire myriad and pentad with one shot!

To add to its interest, access to OV is problematical. Beast Cliff forms part of Britain’s heritage coastline and is also included in a 260 hectare site of special scientific interest mainly on account of its botany and unstable Jurassic geology.

The maps above show from left to right, the 500km squares or pentads of the original National Grid, the land based 100km squares or myriads covering Scotland, England and Wales and the letters of the four myriads that border OV000000 at Beast Cliff.

Zero Points

I first became aware of OV0000 in November 2005 as part of an idea to visit the zero points of the United Kingdom. My wife, Gillian Rimington, thought that it might be interesting to locate all the grid references with six zeros and build up a photographic portfolio of them. Once we started to compile a list of the 22 land based zero points in Scotland, England and Wales we were struck by their rich variety of terrains (see Appendix One for a full list). To test the concept we first visited SP000000, the Fosse Way near Cirencester, but early results were not encouraging. The zero point was in a field of wheat and the nearby roman route of the Fosse Way had become a disturbingly busy trunk road. I took a few photographs but they lacked much interest.

Our second zero point SE000000, Swineshaw Moor, proved more encouraging and as it lies only 15 miles from our home in Bury we have been able to return several times in different weathers and seasons. Swineshaw became the model for tackling other zero points and made us realise that any interest lay not so much in exact zero points but more in their locality.

This led us to develop the concept of the zero grid quartet (also known as zero tetrads), that is the four kilometre squares that border a zero point. Modern OS maps actually identify the quartets by over printing four sets of different myriad prefix letters. Exploring grid quartets gives a much better feel of the country around each zero point, so as well as recording the exact points, we have extended our photographic mission to include interesting features within each quartet.

Discovering the National Geograph Project

In March 2006 I was searching the internet for information on ‘Redbourne Hayes’ our title for the zero point TA000000. This introduced me to David Squire’s photograph and first geograph of the TA 0000 square. Until then I had never heard of geographs but I soon realised that that our Zero Point Project and the National Geograph Project had much in common. In particular the neologism ‘myriad’, referring to a 100km square, tied in very nicely with zero points which are by definition the meeting points of four land myriads. My first contribution to the Geograph project was a picture of TM0000, Dengie Marshes in Essex, which I reconnoitred on March 4th 2006.

Early Attempts on OV 0000 (Beast Cliff)

Also on March 4th 2006 Gillian attempted to visit OV0000 in North Yorkshire. She grew up near here, her late father Frank Rimington wrote a book on Staintondale which includes Beast Cliff and her mother still lives in Burniston, a few miles south of OV. We therefore knew the area very well but had never descended to the coast at this point. Gillian was lucky to encounter some spectacular wintry weather recorded in her dramatic geograph photo of War Dike SE9999. However although War Dike is only 500 metres away from OV0000 a direct descent down Beast Cliff looked impossible. On a subsequent visit she explored the cliff top more thoroughly and spotted some possible ways down further north near Common Cliff.

SE9999 : War Dike by Gillian Rimington War Dike Gate in winter

Successful Visit on July 15th 2006

By July 2006 we had reconnoitred 15 of the 22 zero points and were determined to solve the problem of access to OV. From the Cleveland Way the foreshore of OV is visible through binoculars but the actual zero point is hidden from view below a lower tier of unstable shale and sandstone cliffs immediately above the high tide line. Just below the Cleveland Way there is an upper tier of cliffs of oolitic limestone and between the two tiers is the undercliff, a broad shelf or plateau covered in dense vegetation. Although the OS map shows a 3 kilometre footpath traversing this plateau from Petard Point, the line of this is virtually impossible to locate in July when the bracken is at its tallest. A couple of days before our visit we checked the Geograph website to make sure the square was still untouched and were interested to find a series of messages from Fasgadh and others suggesting that OV might require a boat and that it could even be the ‘mythical last great problem’ of the entire national grid. Studying the 1:25000 map and aerial photographs there appeared to be a generous foreshore running from Ravenscar, south to OV and we decided that this was our best approach. But just to be on the safe side I packed a climbing helmet and a 60m rope with abseiling and prusiking equipment resurrected from my caving days.

With fantastically hot weather, no wind and low tide at 1410 BST, conditions were perfect. Parking at War Dike Gate we headed north along the Cleveland Way beyond Common Cliff to NZ990010. From here it is possible to drop down a steep slope, which at first is fairly free of thick vegetation, to reach the plateau. Crossing this involves fighting through dense undergrowth, mainly bracken but with some brambles and stinging nettles thrown in for variety. Perhaps it was fortunate at this stage that we were blissfully unaware that the plateau is also riddled with adders and ticks.

We were just starting the traverse of the plateau when we were shocked to see two figures beating a path through the bracken and heading towards us from the direction of Ravenscar. Gillian surmised that this must be a raiding party from Scotland led by Fasgadh and intent on bagging OV0000. She suggested sharpening our walking poles in case there was a confrontation at the grid square. However a little later the party turned northwards to Blea Wyke Point where they revealed themselves as harmless fishermen. After about 30 minutes we reached the beach with our GPS reading 1.25 kilometres to OV. Fortunately the sun had by now thoroughly dried the rocks of the foreshore so traversing and jumping between boulders proved straightforward.

NZ9901 : In search of OV 0000 by Peter Standing Approach to OV 0000 near Common Cliff

OV0000 : Meeting of the Myriads by Peter Standing
Just before OV we found a colourful fishing buoy wedged between the boulders and thinking that it could be useful as a temporary marker I managed to prise it free. We reached our goal just after low tide with a calm sea over 50 metres away. After taking the average of several GPS readings I positioned the buoy on the approximate location of the OV zero point and then realised that I had acquired a useful photographic prop.

We spent some time recording and exploring the vicinity of the OV zero point making a number of discoveries. First there was some large metalwork exposed by the low tide which we later learnt was a ship’s boiler, possibly from the Premier, a Grimsby trawler, wrecked in 1923. But our biggest surprise was finding a short green ladder in a steep gully just north of OV. Figuring that this might be some direct route back to the Cleveland Way we climbed up and were soon at the top of the first cliff. Despite yellow paint marks on a rocky outcrop above we failed to locate any clear onward path and had to resort once again to jungle bashing across the plateau . In July this direct route is very challenging because apart from the dense undergrowth of the plateau there are boulder fields with hidden holes and chasms. Finally one has to find a way through the steep and loose oolitic limestone tier of Beast Cliff which lies directly under the Cleveland Way.

National Geograph Race to complete the first Myriad

I submitted the photo of OV0000 on Monday July 17th 2006 unaware of the intense interest in completing the first myriad as reported in the geograph discussion topic ‘Race for the First Myriad’. It was only on the following day that I came across this discussion group and also discovered that overnight, OV had shot up from obscurity to top position in the myriad league table and that I was the first person to complete a myriad. To those who were close to achieving this dubious honour I offer commiserations but don’t despair. There are still thousands of other interesting geographs left to photograph and OV itself holds plenty of challenges such as

HAM Radio Visits to OV

Anyone who thinks that geograph photographers are, dare I say this, a little obsessed with grid squares, might try investigating the world of amateur radio enthusiasts. They discovered OV in 1977, years before the Geograph Project was born and have visited the site many times since, executing their radio transmissions in the style of small military expeditions. To reach their target they were often equipped with saws, ladders and ropes and all this whilst carrying backbreaking loads of portable radio gear. Because of its difficult access and tiny land surface OV is a highly prized 10km WAB square (or hectad in geograph speak). The original concept of transmitting from OV came from Alec Brennand whilst Dennis Binns provided the surveying expertise and Graham Slack subsequently wrote up the project. Access was initially from Ravenscar via Blea Wyke Point. The first proper activation of the site occurred on September 18th 1977 and 57 contacts were made. OV became a household name - at least in the houses of WAB members.

The website LinkExternal link features an interesting and amusing illustrated account of OV by John Earnshaw known as John G4YSS in radio circles. There is one splendid picture of an adder on the Cleveland Way. Had I discovered this account earlier it might have saved us much effort although it would have detracted from the excitement of our own adventures. At least we have now cleared up the mystery of the ladder on the lower cliff. It was fixed there by John in April 2006. I have recently corresponded with him and learnt much about the development of the radio route to OV. John Earnshaw is an authority on OV having visited it between 60 and 70 times with around 35 radio successful activations. He was careful to resurvey the area in case the original radio transmission had accidentally been made from outside the square. Had this been the case hundreds of radio contact records would have been invalidated but fortunately he was able to roughly confirm the original survey. Some idea of just how difficult OV radio transmissions are may be gathered from some of John’s technical notes -:

‘Eventually, after 20 descents between April and July 1987, I had completed the protected approach route and rawlbolted a 40 lb 'mast stanchion’ to a rock between the tide lines. To this I had 'U' bolted a 27 ft tree, gleaned from the plateau, with 3 steel cable stays. On top of this was a 40 m long dipole antenna, fastened back to the cliff top with line. The coax feeder ran underwater to the mast. The mast was there for a month but was then mistaken, by a passing fishing boat, for a yacht on the rocks. 3 lifeboats were launched and the Coastguard had to descend to have a look, but enough said about all that. I had already been reported to the police for acting suspiciously at War Dyke’. John concluded his e-mail to me by saying ‘I am pleased that you read my article and am amused by your discovery of a bunch of parallel 'weirdoes,' i.e. WABers!.....’.

The 1987 radio route was destroyed by weathering and the rapid erosion that is very much a feature of the Beast Cliff area. The current 2006 route follows a slightly different line but in time this too is likely to suffer the fate of its predecessor. Remnants of radio transmissions can still be seen at OV including the corroded 12mm bolt in my photograph and a steel stanchion sticking from under some rocks.

Planning a visit to OV 0000

Any competent walker with exploratory zeal and plenty of self reliance will have no difficulty getting to OV0000. Visitors should be aware that the area does pose potential hazards, including trips over dense undergrowth, disappearing down hidden holes, injuries from loose rocks, adder bites, being cut off by high tides or washed out to sea by freak waves. I returned from my trip with four ticks embedded in my skin and tick bites carry a small risk of Lyme Disease – see LinkExternal link.
Those approaching OV via the plateau would be well advised to wear long trousers, a long sleeved shirt and to carry a walking pole. Knowledge of tide times is essential and the safety of any old ropes or ladders on the radio route should not be trusted. Beast Cliff is an unsympathetic guardian of fixed equipment.


OV0000 : Below Beast Cliff by Peter Standing Lower tier of Beast Cliff from OV

NZ9900 : En route to OV 0000 (2) by Peter Standing Foreshore near Rocky Point

OV0000 : Radio Bolt at OV by Peter Standing Radio Bolt from 1987 at OV

OV0000 : Shipwreck at OV by Peter Standing Shipwreck at OV


National Grid – the Ordnance Survey’s system for map referencing any point in the UK. It is based on part of an earlier military grid made up of 25 squares of 500 km by 500km, each prefixed by a letter of the alphabet. The missing letter is I. The military grid spreads far out into the Atlantic, up to Iceland and onto the Western European mainland. Only five squares H, N, S, O and T cover the UK land mass. The prefix letter is the first to be quoted in a National Grid reference.

Geograph Project and Squares - The Geograph British Isles project (LinkExternal link aims to collect geographically representative photographs and information for every kilometre square of the UK and Eire.

Myriad – The Geograph Project’s name for a 100 kilometre square of the Ordnance Survey’s National Grid. Each myriad has a two letter prefix quoted in National Grid References and contains 10,000 kilometre grid squares.

Pentad – The Geograph Project’s name for a 500 kilometre square. A pentad is made up of 25 myriads.
Zero Point – The intersecting point of four myriads. The grid reference such as OV000000 for a zero point will adopt the prefix of its north easterly myriad.

Zero Grid Quartet (or Zero Tetrad) – The four kilometre squares around a zero point. Each belongs to a different myriad.

Foreshore - that part of the seashore between the high and low water marks.

WAB – Worked All Britain (LinkExternal link – the name of an amateur radio organisation which fosters a competitive spirit amongst its members. The Worked All Britain (WAB) award scheme for radio amateurs runs on a points system for either activating (transmitting from) or working (making a two way contact with an amateur radio station in a square) using the NGR 10km grid squares, supplemented by the County or Unitary Authority (so each 10km square can be split into more than one WAB 'area').

Fasgadh – The web name of Richard Webb, a prolific contributor to the National Geograph Project. By July 2006 he had submitted more than 5000 first geograph photographs, 3000 ahead of his closest rival.

Further Reading

‘Cleveland Way – National Trail Guide No 3’ by Ian Sampson. Updated 2003.

‘Geology of the North York Moors’ by Alan Staniforth, published by the North York Moors National Park. This little book includes sections on the coastal geology between Ravenscar and Scarborough.

‘Worked all Britain Awards Group’ 2005 (Book or CD). This can be ordered via the WAB website.

‘Shipwrecks of the Yorkshire Coast’ by Arthur Godfrey & Peter J Lassey. Dalesman Press (out of print).

‘The History of Ravenscar and Staintondale’ by F.C. Rimington. Monograph published in 1988 by the Scarborough Archaeological and Historical Society. 99pps. Chapter IV explains the origins of the place names, Undercliff, Common Cliff and Beast Cliff and that in former times parts of the undercliff allowed the grazing of cattle.

‘Beast Cliff Site of Special Scientific Interest’. Information on this may be found at
LinkExternal link


I am indebted to John Earnshaw for information about OV and for permission to quote from his e-mails. It was thrilling to hear from David Andrews, who surveyed OV for the Ordnance Survey over 30 years ago. His recollections, quoted with his permission in Appendix Two, give a valuable insight into the workings of the OS at the time. Within the National Geograph Project I am grateful to Martin Addison and Kevin Hale for valuable feedback posted on the OV discussion forum and to developer Barry Hunter for his encouragement and technical help in publishing this article on the Geograph website. But most of all I would like to thank my wife Gillian for coming up with the mad idea of visiting the zero points and for her company on many of my expeditions to them.

Appendix One

The 22 Zero Points of Scotland, England and Wales
1NBTaransayHebridean Island - uninhabitedWestern IslesWest of South Harris61
2NHAllt a MhaingarMountain Valley & RiverHighlandS of Loch Quoich, W of the Munro of Gairich312
3NJCarn EtchachanSub Arctic Cairngorm summitGrampian2km NE of Ben Macdui1060
4NNBeinn GhlasMountain MoorlandStrathclydenear Furnace, north Loch Fyne309
5NOPool of MuckhartGolf Course & FarmlandTayside10km SE of Auchterarder135
6NTPot of AeMountain Moorland & ForestryDumfries & Galloway1km east of Queensberry (697m)476
7NUCoquetdaleFarmlandNorthumberland6km WSW of Rothbury142
8NZCringley BottomMoorland Field Systems & BarnsNorth Yorkshire4km west of Reeth, Swaledale356
9OVBeast CliffNorth Sea Coast & SSSINorth Yorkshire10km N of Scarborough0
10SESwineshaw MoorPeat Moorland & ReservoirsDerbyshire3km N of Tintwhistle365
11TARedbourne HayesFarmlandLincolnshire7km S of Brigg5
12SJMynydd Pistill-duFarmland & MoorlandPowis12km NW of Newtown362
13SKPoukhillUrban, Canal & Electricity SubstationBirmingham2km NE of Walsall138
14TFFineshade WoodAncient and New WoodlandNorthamptonshireRockingham Forest near Stamford88
15TGLittle EllinghamFarmland and villageNorfolk12km S of East Dereham46
16SNAllestonFarmland & Suburban FringeDyfed2km S of Pembroke46
17SOCwmamanMoorland above ex pit villageGlamorganRhondda Valley314
18SPFosse WayFormer Roman Road through FarmlandGloucestershirenear Cirencester124
19TLGreat White EndFarmland & WoodlandBuckinghamshire4km NE of Amersham138
20TMDengie MarshesFenland and FarmlandEssex4km NE of Burnham on Crouch1
21STSide DownsWoodland & Country ParkDevon8km NNE of Exeter118
22SUJulians BridgeHistoric TownDorsetWimborne Minster18

This is a preliminary list of the 22 zero points which are located on land in Scotland, England and Wales. Comments or corrections are welcome and the author may be contacted via the Geograph website.

Peter Standing – September 2006

Appendix Two - OS survey of OV by David Andrews

On September 24th 2006 a former OS Surveyor, David Andrews, posted a message on the discussion forum for OV.

So pleased to have found this web page! In the late 1960s, (or early 1970s - I cannot remember the exact date after all this time), I had the privilege of being the Ordnance Survey surveyor to "Overhaul" the 1:2500 scale plan OV0000. "Overhaul" was the process of revising the County Series map onto the new National Grid sheetlines and bringing the map detail completely up to date. In my 39+ years working as an OS surveyor it was the only plan that I managed to revise without actually setting foot on the plan! Low Water Mark had previously been surveyed by aerial photogrammetry at OS headquarters in Southampton. The bottom of the cliff was surveyed by me from rectified aerial photographs, and the foreshore detail was observed by me from the cliff top through binoculars. I have waited for a long time to see this map acknowledged, and finally you guys have done it. Thank you, you have made an old surveyor very happy.

David Andrews worked for the Ordnance Survey from 1964 until 2003 and was based in Scarborough for 8 years when his involvement with OV occurred. He worked initially on the 1:1250 graphic survey from tacheometric control and later was part of a team revising the 1:2500 scale mapping on the North York Moors and the area bounded by Whitby, Pickering, Helmsley, Malton and Flamborough Head. I have been in contact with him for more recollections about his survey of OV.

My memory is not good enough to recall the exact time, except that it was summer rather than winter and must have been sometime between 1968 and 1972. As for where I was standing, it would have been at several points anywhere along that stretch of coast where I could see anything of the foreshore around OV0000. The map I was revising was at 1:2500 scale. I needed to be able to see the nature of the foreshore detail (flat rock, boulders, sand, shingle, mud etc) as this would be noted on the field plot and would indicate to the draughtsman what symbol(s) to show on the published map.

He explained more about the processes of OS mapping at the time.

Overhaul was the process of recasting the old 1:2500 plans on individual County sheet lines and county based Cassini projections onto a national system of sheet lines based on the National Grid and at the same time transforming them onto a national Transverse Mercator projection. The old plans were quite literally cut up with scissors to fit the correct computed National Grid positions of the network of triangulation stations on the Transverse Mercator projection. Surveyors like me then went on site to smooth out the joins of the scissor cuts and bring the maps fully up to date. OS started using the metric system immediately after WW2. This was the result of the recommendations of the Davidson Committee set up in 1937 to make recommendations on the scale, sheet lines etc for the national maps. WW2 delayed the implementation of the recommendations, (OS still being a military organisation at that time). Following the war the 1:1250 scale of mapping was introduced for major towns, 1:2500 for cultivated land, and 1:10,000 scale for mountain and moorland. At the same time the National Grid system was introduced, with all OS mapping on the Transverse Mercator projection, and all large scale sheet numbering based on the National Grid.

Most Low Tide surveys, (and of late most High Tides as well), are surveyed from Infra Red aerial photographs. Infra Red photography shows up water as very dark so therefore easier to identify the water’s edge. The photography is flown at the predicted time of a Mean Low/High Tide. After flying, contact is made with local Port authorities to check that the actual tide height was the same as predicted.

1:2500 scale maps cover an area of 1Km X 1KM, (each one being one of the grid squares on a 1:50,000 scale map). The 1:25,000 and 1:50,000 scale maps use the larger scale survey material as a base and then are generalised to edit out the inevitable clutter of minor detail but retain the shape and sense of the detail to be shown at the smaller scales.

Once the 1:1250 and 1:2500 National Grid maps were surveyed or Overhauled they became subject to Continuous Revision. Change to ground features was monitored by the local survey office using whatever means on intelligence could be used and each map would be republished when a set amount of change had been surveyed on it. With the advent of digital mapping maps are no longer published as paper new editions, but the large scale mapping database is updated daily with each day’s survey work by OS offices nationwide and the updated surveys are available to the public within a couple of days of the survey through a network of agencies in major towns. The OS website confirms that the latest update to OV0000 occurred on 23rd March 2005, but what the change was is not stated.

You are not logged in login | register