Being a working MOD site, it's difficult to get access unless you have business there, but if you can arrange a visit there's loads to see. The walls of the citadel house a Chapel dedicated to the Submarine Service, crammed with fascinating memorials and artifacts. The sea wall still has the emplacements that housed the guns which were to defend Portsmouth and Gosport from attack from the sea. Its possible - with care - to walk around the old walls and see how the naval base grew up around the original fortress. Amazing place.

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