The Spinnaker Tower is a 170-metre (560 ft) landmark tower in Portsmouth, England, UK. It is the centrepiece of the redevelopment of Portsmouth Harbour, which was supported by a National Lottery grant. Its shape was chosen by Portsmouth residents from a selection. The tower, designed by local firm HGP Architects and engineering consultants Scott Wilson and built by Mowlem, reflects Portsmouth's maritime history through its being modelled after a sail.