I was lucky enough to be working at Hurst Castle just off the south coast and practically opposite the Isle of Wight. Building work started here in 1540 or thereabouts on the orders of Henry V111, and it was modernized during the Napoleonic wars and again in the 1860s when the armored "wings" were constructed. It was manned again during WW2 with coastal gun batteries and searchlights, but now it has a more sort of relaxed tea room vibe, it has some fantastic views and a museum. Most under-rated museum ever. I recommend.