 In 1830 the East Tunnel, which linked the north and south parts of the zoo together for the first time, was completed, which also acted as a bomb shelter during World War II.Burton concluded his work in 1837 with the Giraffe House, which, due to its functional design, still remains in use as the zoo's giraffe enclosure in the "Into Africa" exhibit.After Burton, Sir Peter Chalmers Mitchell and John James Joass were appointed to design the Mappin Terraces.