Geograph - photograph every grid square

A major teaching hospital situated on the western edge of Leeds City Centre, the LGI (as it is locally known) boasts that it has been "saving lives for 250 years". Its origins are in an Infirmary “for the relief of the sick and hurt poor within the parish of Leeds” in a private house in Kirkgate in 1767. It was soon replaced with a purpose-built hospital opened in 1771 close to City Square, which in turn was replaced by the present main building on Great George Street, designed by Sir George Gilbert Scott and opened in 1863. The hospital has expanded several times since, including the Brotherton Wing in 1940 and the Jubilee Wing in 1998. The Seacroft Hospital opened in 1904 to the east of the city and is now part of the same NHS trust.
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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%)

Read more at Wikipedia Link