The Clock Tower is the earliest surviving building at London Zoo, although it has twice been rebuilt. It was constructed as a 'Gothic House for Lamas', but was soon given over to camels. It was built in 1828 and designed by the architect Decimus Burton. The clock turret was added in 1831 and rebuilt in 1844. It was reconstructed 'in an improved form' in 1897-98 by Charles Brown Trollope, architect; George Smith and Company, builders. It was bomb damaged in 1940 and wholly rebuilt 1946-47 by Burnet, Tait and Lorne, architects. It was converted to a chair store in 1958 and shops in 1988. It is Grade II listed.
The Stork and Ostrich House was built to plans by Charles Brown Trollope in 1896-97; George Smith and Company, builders. It cost £3,788. in 2013 it was incorporated into Tiger Territory.
The Aquarium is housed under the Mappin Terraces. The space had been set aside for an aquarium from 1913 when the Terraces were laid out, but detailed planning was deferred by war until 1921-22. Briefs were provided following visits to aquariums in Amsterdam, Antwerp, Brussels, Berlin and Dresden. It was built 1923-24, brief by E G Boulanger, Curator of Reptiles; John James Joass, architect; Alexander Gibb and Partners, engineers; J Jarvis and Sons Limited, building contractors; Joan Beauchamp Procter, rockwork design; cost around £55,000. Refaced to west 1951, and to east 1965, Franz Stengelhofen, architect. Grade II listed. The Aquarium closed on 22 October 2019. Some animals were moved to a new aquarium at Whipsnade Zoo, while others were set to be housed in a new corals exhibit in the B.U.G.S. building in 2020.
Electricity was installed in the rest of the Zoo when the Aquarium was built.
The Owls' Aviary of 1905 is a pheasantry-like structure with caging around as if with a 'palace front'. The 100 ft (30 m) row consists of fifteen open cages in front of simple shelter huts, probably of timber originally but rebuilt in concrete blocks.
