Portsdown Main: The old Art Deco building on the hill which once overlooked Portsmouth

On the top of Portsdown Hill and overlooking Portsmouth once sat an enormous Art Deco-styled building which was known locally as Portsdown Main – or the ASWE.

The site was designed in the 1930s, but was not built until the 1950s as a result of the Second World War, and was synonymous with defence research being used by different government departments until its eventual closure in 1997.

Built on Portsdown Hill in 1952 as the Admiralty Surface Weapons Establishment (ASWE), it was later known as the Admiralty Research Establishment which was a department of the British Admiralty. Later it was run by the then Navy Department, now the Ministry of Defence, and responsible for research and development of devices, equipment and techniques for naval communications and radar missile control from 1959 to 1984.

There were over 30 buildings on the 46 acre site built between 1946 and 1955 with Portsdown Main being the most iconic. To the west is Fort Southwick and to the east are two further distinct sites on Portsdown Technology Park. Portsdown Main finally closed in January 1997 and although a number of government departments were interested in the site, none moved there. In 2002 it was announced that the Defence Science and Technology Laboratory was going to move back, but this was later cancelled.

The building was put on the open market but a buyer was not found, leading to demolition of the site which started in 2010 and was completed in 2011. However some parts remains including the former guard posts which are now due to be converted into takeaways.

News you can trust since 1877
Follow us
©National World Publishing Ltd. All rights reserved.Cookie SettingsTerms and ConditionsPrivacy notice