Historic defences revealed near Southsea Castle

Amazing insights into the history surrounding Southsea Castle have been revealed during excavation works for the Southsea Coastal Scheme flood defence project.

A structure designed to hold a swivel mount gun dating back to the early 19th century has been exposed beneath the existing promenade in front of the castle.

In addition, a large triangular defence structure has been found near the gun emplacement. This is thought to be the remains of a revetment constructed as part of the late 17th century redesign of Southsea Castle, representing an earlier phase of the historic defences.

Southsea Coastal Scheme Project Director Guy Mason said: “These remains are extremely important to Portsmouth and provide a strong link to the history of Southsea Castle.

“We’re pleased to be working well with Historic England and Wessex Archaeology to agree on how to best adapt our design around the finds, just as we did with our design around the historic walls discovered near Long Curtain Moat.

“In the meantime our team has worked quickly to ensure the remains have been covered for protection from extreme weather and tidal conditions.”

Principal Consultant for Wessex Archaeology Alex Godden said: “These well-preserved remains offer a fascinating insight into the development of Southsea Castle over the past 350 years.

“The triangular defence structure appears likely to be part of the redesign of the castle by the Dutch military engineer Bernard de Gomme.

“It’s exciting that as a result of the archaeological excavations we can see the physical evidence of the large scale upgrading of the historic defences of Portsmouth that took place in the late 17th century.”

“In addition, the discovery of the 19th century swivel mount shows us how the defences have been adapted and continued to evolve over centuries.”

Historic England Inspector of Ancient Monuments Iain Bright said:

“Southsea continues to offer us tantalising glimpses into the rich history of its nationally important historic sites. Incorporation of the 17th century structure as a feature of the new promenade will allow it to be enjoyed and understood by visitors for years to come.

“The entire team has been exemplary in their approach to – and understanding of – the importance of Portsmouth’s heritage. By working collaboratively and reacting smartly to this discovery, we have ensured these remains will be preserved as part of the story of the castle and its defences. That story continues today with the construction of the new sea defences.”

The Southsea Coastal Scheme is the UK’s largest local authority-led coastal defences’ project, worth more than £160M. It will stretch for 4.5km from Old Portsmouth to Eastney.