The next time you’re on vacation, don’t forget to send some postcards back home. If you happen to visit the Japanese fishing town of Susami and you like to dive, you can use the world’s deepest underwater mailbox, which is submerged about 33 feet (10 meters) below the surface of the bay. The mailbox is used by divers who buy water-resistant postcards at a nearby diving store and write messages with oil-based markers. An employee of the shop regularly dives for the postcards and takes them to the post office.
Wish you were here: