The northeastern corner of Regent `s Park is occupied by the London Zoo, which was founded in 1826. Over the past decade, the zoo has tried to redefine itself as an environmentally friendly place whose main purpose is to save endangered species. The zoo has some notable features of the architecture, like the modernism of the 1930's, the spiral ramp, a penguin concrete pool designed by the company Tecton, directed by Russian émigré Berthold Lubetkin, who also did the Zoo 'Round House. The Giraffe House, by contrast, was designed in neoclassical style by Decimus Burton, who is also responsible for the clock tower Tudor.