世界で一番深い郵便ポスト
In Japan, there is a very special mailbox located underwater! It is in Susami Town, Wakayama Prefecture, and it is about 10 meters deep in the ocean. Divers can mail waterproof postcards from this mailbox. It was even recorded in the Guinness World Records as the world’s deepest mailbox. Many people visit this place to enjoy diving and sending unique underwater letters!
