The initial grounds were laid out in 1828 by Decimus Burton, the zoo's first official architect from 1826 to 1841, made famous for his work on the London Colosseum and Marble Arch. Burton's work began with the Clock Tower in 1828 above what was then the llama house, which today is the first aid kiosk. 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.