The Greek ship YDRA. Built in the UK in 1966 and named Manchester Fort. But became a Greek ship and renamed YDRA. Ran aground on the coast of Tunisia on 21 January 1983 after a fire in the engine room.
The ocean floor is littered with millions of shipwrecks, but we only know the locations of a small fraction, and we've explored only a small fraction of those. Will the treasures of these sunken ships ever be hauled up from the deep?