Henry VII built this fortress. It was one of the most advanced artillery fortresses in England. Cannons were mounted here.  Used as an air base for seaplanes during the World War. And it was deliberately set at one extreme end of a coastal spit, closest to the ocean, plenty of things to see and do. The castle is split into two areas, one for the history of the war and the other for the monarchy. Amazing panoramic views from the top of the castle. Very informative and plenty to see. You can either walk about a mile across the beach to reach the castle or pay to take the boat.