Green Citadel, Magdeburg

The pink Green Citadel, so-named for the wildflower meadows and trees on its roofs, was the final architectural work of Viennese artist and architect Friedensreich Hundertwasser. It is home to 55 individually-designed apartments, an hotel, offices, shops, cafés, a 200-seat theatre, medical practices, and a kindergarten.

Its striking Gaudí-meets-Williams-Ellis style marks it out very distinctly from the Baroque buildings that surround it, and from the Communist-era rational architecture that dominates residential Magdeburg.

The Housing Association of the City of Magdeburg commissioned Hundertwasser in 1998 to refurbish the prefabricated concrete high-rise that used to occupy the site. The scheme was abandoned in favour of a new build, and ground was broken in December 2003, three years after the architect's death. The plans, sketches and scale models had, however, all been completed, and the complex opened to the public in October 2005, at a build cost of circa €27million.

Hundertwasser developed a manifesto in which he stated: "Architecture [must be] true to nature and humans." The residential leases grant a 'window right': "A resident must have the right to lean out of his window and to refinish everything within arm’s reach on the outer wall, so that people can see from afar, 'A free man lives there'; [and] may refinish the outer wall of his apartment around the window in a creative and original way ..."