 The Modernist dual concrete spiral ramps of the Penguin Pool have made it famous as a piece of modern architecture, but in 2004 the African penguins were moved out of the pool permanently due to it being an unnatural environment for them.The Snowdon Aviary, built-in 1964 by Cedric Price, Lord Snowdon and Frank Newby, made pioneering use of aluminium and tension for support.A year later the Casson Pavilion, designed by Sir Hugh Casson and Neville Conder, was opened as an elephant and rhinoceros house.