On the beach between Bognor Regis and Aldwick lies the wreck of a floating pontoon (caisson) which was once part of the Mulberry floating harbours used by the Allies to invade the French coast on D-Day 6 June 1944. It was a part of the Mulberry harbour which broke free in a storm on 4 June, the day before it was due to go over the channel to Arromanches. This particular section of Mulberry was abandoned and did not make it across the Channel. It was washed up on the beach shortly after D-Day.