Construction began in 1968 and was completed in 1971. Its 15,372 residential units, in 35 high rise buildings and seven clusters of townhouses, make it the largest single residential development in the United States. It sits on but only 20% of the land was developed, leaving many green spaces. The apartment buildings, referred to by number, range from 24 floors to as high as 33. The 236 townhouses, referred to by their street-name cluster, are three stories high and have a separate garden apartment and upper duplex three-bedroom apartment.