Robin Hood Gardens is a council housing complex in Poplar, London designed in the late 1960s by architects Alison and Peter Smithson and completed in 1972. It was intended as an example of the 'streets in the sky' concept: social housing characterised by broad aerial walkways in long concrete blocks, much like the Park Hill estate in Sheffield, and as a British response to projects like Le Corbusier's Unité d'Habitation. However, there were problems both with the quality of construction and the general design of the estate, which was plagued by crime. The project is generally regarded as a failure and the Smithsons' architectural career never quite recovered.