Pevensey Castle is the ruin of a fortification that goes back all the way to the Roman invasion of England, with additions/modifications made from William the Conqueror to WWII. It must have been a very impressive sight back then, and there's enough of that left to justify a trip to Pevensey Bay. If you visit by train, be aware that connections along the Hastings to Brighton line are few and far between on the day, with two connections in either direction in the morning, and two in the middle of the afternoon. So plan your visit carefully. The castle is now being maintained by National Trust, the ticket will cost you UKP 6.90 for an adult (concessions available). Expect to spend 1-2 hours on the premises. You can walk the grounds of the castle for free, only the access to the "inside" is charged. As to be expected, no real "rooms" of the castle proper still exist, but you'll get access to a couple of towers (since those were restored for use in WW2). There's a small exhibition on the history of the castle, which is rather nice. Would have been even nicer had I not had the misfortune of a teenage student group visiting the castle at the same time. Ugh, teenagers. Double ugh, British teenagers. Anyway, I certainly enjoyed the trip own history lane, the clerk at the entrance was very helpful too - plus an audio guide is included with the ticket. Which proved to be very informative, even if the narration at certain points of interest went on and on and on. ;) I finished within one hour, which was the same time spent on the premises by those teenagers. All in all, if you happen to be in Eastbourne or Hastings, it's totally worth the trip. And if you're caught in Pevensey for some hours more, as I was, make sure to walk up to the beautiful seafront, enjoy Fish and Chips from Rosie's Fish Bar, and just unwind.