World's deepest underwater postbox is on Malaysian seabed
The deepest underwater postbox in the world is located at a depth of 40 metres, on the seabed in Pulau Layang-Layang, Malaysia. Visitors can send postcards stamped with a special postmark and the logo of Malaysia Book of Records. There are several similar postboxes in the world, with a postbox in Vanuatu providing visitors with waterproof postcards. 