The wreck of the German World War I submarine U-118 is visible on the beach at Hastings at low tide. The submarine was a mine-laying U-boat that surrendered at the end of the war and was being towed to France in 1919 when it broke free in rough weather and was driven ashore on the beach west of the town centre.
The wreck became a strange tourist sensation in the 1920s, with postcards, guided tours, and crowds who came to see the enemy submarine in person. Over decades of exposure to weather and sea, the hull has broken up and corroded to scattered sections, but the outline of the submarine is still discernible at extreme low tides. It is an accessible piece of First World War history that you can literally walk up to.