Abandoned Hampshire: Hilsea Lines- Portsmouth

External view of Hilsea Lines

Portsmouth is famous for its naval connections and there is evidence of this throughout the city. One such place is Hilsea Lines, which is one of the easiest abandoned locations to explore in Hampshire. The “Lines” are a two-mile long rampart structure of both chalk and earth. These mounds are 9 metres high and 20 metres wide. There are six armoured and bombproof casemates, designed to house guns and artillery. Most have been converted into recording studios and a cafe, however Bastion 5 remains abandoned.

See other abandoned places in Hampshire

Pre – 19th Century Hilsea Lines

The site was once a military base and its history dates back to 1544. Due to Portsmouth’s proximity to England’s biggest rival, France, Henry VIII developed the area as a military and naval base. The first defences in Hilsea were built north of Ports Creek to protect the naval bases from land attack. It was not until 1757 that defensive lines were built south of the creek to protect the land from naval attack. In 1858 the threat from France increased and the Hilsea Lines were strengthened, costing £260,000. However these lines were replaced in 1871 with the defences that you can see and explore today.


In 1886, concrete gun pits were installed on the bastions. These allowed moveable armament to be placed in the area. It is unknown how the site was used in World War One however anti-aircraft guns were placed on the Lines. Trees were also planted on the top of the ramparts to try and break up the shape of them. Between WWI and WWII one bastion was converted into changing rooms for Portsmouth Grammar School. In 1933, the western part of the moat was used as a boating lake and lido! During WWII anti-aircraft guns were installed on the Lines again and these were manned by the Home Guard, but never used. Some magazines were also used as air-raid shelters.

20th Century

In 1986 Portsmouth Council purchased the Lines and today the majority of the defences are hidden in woodland. Portsmouth Grammar School still owns Bastion One and use the land nearby as playing fields. Thankfully our European enemies have never reached Portsmouth’s soil and so these defences have never seen military action!

Last Updated on 17 November 2021 by Michael


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