Thousands of people visit the popular centre every week for its shops, eateries, cinema, bowling alley and bars - but do you remember when it was first built?
For years the Royal Navy had used the site as the torpedo training school HMS Vernon until it was closed in 1986.
A decade later Portsmouth City Council approved the planning application for the new Gunwharf development and construction work began in 1998.
Three years later in February 2001 the shopping centre opened its doors to the public to the first time.
Now its owners have announced a £45m investment programme to improve it - including solar panels, new walkways and lighting - which will help to ensure its popularity with visitors remains.
We have had a look in the archive and found some photos of the construction – what do you remember?
. Gunwharf Quays construction
Gunwharf 16th January 2001. View of the Gunwharf developement, taken from the site Marketing Office. Picture: Ian Hargreaves 010262-5 Photo: The News archive
. Gunwharf Quays construction
Gunwharf Quays being developed in 1999 Photo: The News archive
. Gunwharf Quays construction
Vernon pool, a view from the upper penthouse level of Blake House, looking towards the commercial development in Gunwharf Quays, Old Portsmoouth. Picture: Michael Scaddan. 011686-0086 Photo: The News archive
. Gunwharf Quays construction
23rd January 2001. Road signs point the way to the Gunwharf Quays development. Picture: Allan Hutchings 010395-1 Photo: The News archive
. Gunwharf Quays construction
The Gunwharf development 10th February 2001, viewed from Old Portsmouth. Picture: Malcolm Wells. 010784-3 Photo: The News archive
1. Gunwharf Quays construction
Gunwharf Quays being developed in 1999 Photo: The News archive
2. Gunwharf Quays construction
Vernon pool, a view from the upper penthouse level of Blake House, looking towards the commercial development in Gunwharf Quays, Old Portsmoouth. Picture: Michael Scaddan. 011686-0086 Photo: The News archive
3. Gunwharf Quays construction
23rd January 2001. Road signs point the way to the Gunwharf Quays development. Picture: Allan Hutchings 010395-1 Photo: The News archive
4. Gunwharf Quays construction
Construction workers work on the lower underground car parking level at Gunwharf Quays in 1999. Picture: The News 992549-2 Photo: The News archive