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Listed buildings and structures are officially designated as being of special architectural, historical or cultural significance. There are over half a million listed structures in the United Kingdom, covered by around 375,000 listings.
Listed status is more commonly associated with buildings or groups of buildings, however it can cover many other structures, including bridges, headstones, steps, ponds, monuments, walls, phone boxes, wrecks, parks, and heritage sites, and in more recent times a road crossing (Abbey Road) and graffiti art (Banksy 'Spy-booth') have been included.

In England and Wales there are three main listing designations;
Grade I (2.5%) - exceptional interest, sometimes considered to be internationally important.
Grade II* (5.5%) - particularly important buildings of more than special interest.
Grade II (92%) - nationally important and of special interest.

There are also locally listed structures (at the discretion of local authorities) using A, B and C designations.

In Scotland three classifications are also used but the criteria are different. There are around 47,500 Listed buildings.
Category A (8%)- generally equivalent to Grade I and II* in England and Wales
Category B (51%)- this appears generally to cover the ground of Grade II, recognising national importance.
Category C (41%)- buildings of local importance, probably with some overlap with English Grade II.

In Northern Ireland the criteria are similar to Scotland, but the classifications are:
Grade A (2.3%)
Grade B+ (4.7%)
Grade B (93%)

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The City of London School (CLS) is a boys' independent day school on the banks of the River Thames in the City of London. It is the brother school of the City of London School for Girls (a girls' school within the City).
The School was founded by a private Act of Parliament in 1834, following events starting from a bequest of land by John Carpenter, Town Clerk of London in 1442, for four poor children in the City of London. The original school was established at Milk Street, with the school moving to the Victoria Embankment in 1879, and then to its present site on Queen Victoria Street in 1986. Today, the school provides day education to about 900 boys aged 10 to 18 and employs approximately 100 teaching staff and around another 100 non-teaching staff including contractors.
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