Olympia Hall, 1886 [ILN Picture Library]
NATIONAL AGRICULTURAL HALL, KENSINGTON. ... An extensive block of buildings, popularly known as "Olympia," erected in 1886, and covering an area of four acres. The Grand Hall, 450 feet in length, by 250 feet in breadth, is said to be the largest hall in the kingdom covered by one span of iron and glass. Intended for agricultural shows, and exhibitions of all kinds; hippodrome circus; concerts, &c. The gardens adjoining cover an area of 5½ acres.
Reynolds' Shilling Coloured Map of London, 1895Victorian London - Publications - History - The Queen's London : a Pictorial and Descriptive Record of the Streets, Buildings, Parks and Scenery of the Great Metropolis, 1896 - Olympia
Until the theatre at Earl's Court was built, Olympia could boast the largest stage in London. It is a huge glass and iron structure, with room enough to seat ten thousand spectators, and has pleasant gardens. Situated exactly opposite Addison Road Station, Kensington, Olympia is easily accessible from all parts of the Metropolis. Barnum's Show, the Paris Hippodrome, the Spectacle of Nero, Venice in London, Constantinople, the Orient, and the Sporting and Military Show, have all in turn occupied the building. An admirable innovation was the reserving of seats all over the building, including the cheapest parts. Towards the end of 1895 Olympia came under the management of Sir Augustus Harris.