Also known as the “Millennium Tower”, the £35.6 million building was approved in September 1995 in a bid to create an educational hub for the community.
Work commenced in November 2001 and after four years, the tower opened on October 18, 2005.
On the opening day, the tower welcomed over 1,000 guests in the first three hours, and in the two decades it has been open, it has seen more than 5 million visitors walk through the doors.
To celebrate 20 years of the Spinnaker Tower, we have put together a gallery looking at the construction of the iconic building:
9. Spinnaker Tower
The official opening of the Spinnaker Tower at Gunwharf Quays. Picture: Michael Scaddan | Michael Scaddan
10. Spinnaker Tower
The glass lifts on the Spinnaker Tower. Picture: Steve Reid | Steve Reid
11. Spinnaker Tower
Spinnaker Tower during construction. Picture: Malcolm Wells | Malcolm Wells
12. Spinnaker Tower
Huge piles waiting for shipment from Southampton to Portsmouth where they will be used at the start of construction on the Gunwharf Tower. Picture: Ian Hargreaves/ Mowlem | Ian Hargreaves/ Mowlem