The Royal Navy Physiological Laboratory (RNPL, also known as Qinetiq Alverstoke) was built on the site of the No.5 battery of the Stokes Bay Lines, where the ramparts and 4 magazines survive.
The site was used to study the affects of deep water pressure on humans, animals, and other substances, with the ability to simulate up to 100m depth initially, then 690m later on.
This follows the area's history of diving research as the neighboring site used to be the Submarine Mining Establishment (more history).
The chambers now sit outside the Diving Museum just down the road.
