Herkules-Hochhaus, High-rise building in Ehrenfeld, Germany

The Herkules-Hochhaus is a 31-storey residential tower at Graeffstrasse 1 in Cologne's Neuehrenfeld district, 102 metres tall. Its façade is clad in enamelled metal sheets in blue, orange, red and lilac. The silver-edged windows are set in groups of three in a free rhythm, a feature of architect Peter Neufert's "systemic architecture". The building holds 427 flats, from 24 to 33 square metres for apartments and 43 square metres for two-room flats.

The building was completed in 1972 as part of Cologne's urban housing program that promoted vertical residential solutions during the 1960s and 1970s. It represented one of many efforts to address housing needs through high-rise development across the city.

Locals call the tower Papageienhaus, or Parrot House, because of its blue, orange, red and lilac enamelled metal panels. In 2005 the Cologne tourist association awarded it the Saure Zitrone, a negative prize for unattractive architecture. The building has been unpopular with Cologne residents since it opened, and an architecture magazine wrote in its early years: "Die Wohnfabrik schreckt Nachbarn ab" (the housing factory scares off neighbours).

The tower stands at Graeffstrasse 1 in Neuehrenfeld, a short walk from the Herkulesstrasse stop. Four lifts serve the 31 floors, two stopping on even floors and two on odd ones; a ride from ground level to the top takes about a minute. The building is residential, so visitors see the enamel facade from the street.

The top floor holds a swimming pool, a sauna and a party room for residents. Two lifts serve the even floors and two the odd ones, and a ride from the ground floor to the 31st takes about a minute. The building has 427 flats and a caretaker.