There is no shortage of bizarre things in Japan. Off the coast of a small town in Wakayama prefecture, you can find an underwater mailbox - and it’s an actual collection point within Susami’s postal system. Each day the contents are collected from the box, presumably by a deep sea diving mailman, which reportedly contains as many as 200 pieces of mail at the busiest times.  Susami is over a hundred kilometres away from Osaka in a not very densely populated but highly mountainous part of Kinki, Japan. 

Malaysia’s Reef Dive Resort has set up what it believes to be that country’s first underwater mailbox. Any mail sent through this mailbox is sealed inside a plastic bag and postmarked with a special stamp. Vanuatu Post created the world’s first underwater post office. Situated within a marine sanctuary off Hideaway Island, this post office, staffed by a postal employee, can receive mail if you are a visiting diver or snorkeler. The best part? The lines are always short. St. Thomas, USVI, has an underwater post office inside its Underwater Observatory, which means you can get the “underwater stamp” without getting “underwater wet.“

  Link: Reference.com