Oak | at SU064122 | on 25K Single trees on parish boundary, also see TQ0647 : Lone tree by footpath for Oak Pollards |
Oaze | TQ8584 : Chalkwell Oaze | on 50K, word associated with "ooze" |
Obelisk | SK5019 : Garendon Estate obelisk | on 25,50K |
Observation Hide | NY6495 : Kielder Burn Valley from Observation Hide | on 25K Photo is view from hide |
Observation point | SZ3493 : The Starting Platform | on 10K |
Observation Post | TA2638 : Wartime Building | on 25K |
Observation Tower | NS2777 : Clydeport Control Tower | on 25,50K |
Observatory | SY1388 : Norman Lockyer Observatory Sidmouth Devon | on 25K Tourist site |
Oceanarium | SP0586 : National Sea Life Centre | on 25K Tourist site, Sea Life Centre on 50K |
Ochre Pits | at SP573060 | on 25K |
Od | HY5404 : The Point of Od | on 50K, point, from Scandinavian Oddr |
Offenders Institution | NS9178 : Polmont Young Offenders institution | on 25K, HM Young Offenders Institution |
Offices | TQ2980 : Westminster: Old Admiralty Offices | on 25K |
Oil Refinery | TQ7482 : Aerial Photo of Coryton Oil Refinery | on 25,50K |
Oil Storage Depot | TQ7382 : Haven Site | on 25K |
Oil Terminal | SJ3387 : Tranmere Oil Terminal | on 25,50K |
Oil Well | SY9079 : Oil Well, Kimmeridge | on 25,50K |
Old Military Road | NX5756 : Old Military Road, Jenoch Wood | NJ0327 : Old Military Road on 50K |
Old Workings | SX6571 : The Henroost | on 50K |
Open Air Museum | NZ2155 : Beamish Open Air Museum | on 50K, tourist site |
Open Air Theatre | SW3822 : The Minack Theatre | on 50K |
Open Farm | TR0753 : Chilham - Badgers' Hill farm | Tourist site. As "Open Fm" on 50K map, named on 25K. |
Opencast Workings | NS9263 : Polkemmet opencast coal mine | On 50K on 2008 map |
Opera house | TQ4510 : Glyndebourne | on 50K |
Orasaigh | NB1331 : Loch an Strom and Aird Orasaigh | on 50K, tidal island, from Scandinavian, sometimes as Orosay |
Ore terminals | TA1716 : Looking towards Immingham Ore Terminal | on 25K |
Osier Beds | TL2912 : The River Mimram, Hertingfordbury. | on 25K |
Osier Carr | TG2236 : View towards Osier Carr from churchyard gate | on 25K The local word for a plantation of osiers, maybe now the name of the wood |
Otter Haven | NG7822 : Kylerhea Otter Sanctuary | on 25,50K Tourist site |
Outdoor Activity Centre | at SD945909 | on 25K |
Outdoor Centre | NS1658 : Greycraigs Outdoor Centre | on 25,50K |
Outfall | TM0304 : Outfall, Marsh House pumping station | on 25,50K |
Overflows | SE3924 : Fairies Hill cut, bypass weir | on 10K |
Overhangs | NA0900 : North side of Conachair | on 25K |
Owl Sanctuary | TA1564 : Park Rose Owl Sanctuary, Carnaby | on 50K |
Ox drove | SU4661 : Ox Drove | on 25K |
Oyce | ND4290 : Oyce of Herston | on 50K, inlet, mouth of stream, Scandinavian origin |