The World’s Deepest Mailbox
You might think of postcards traveling by air—but in one island nation, they take a dip underwater first.
Off the coast of Hideaway Island in Vanuatu, there’s a fully functional underwater post office, built in 2003. Set three meters below the surface, it’s the only one of its kind where snorkelers and divers can swim down and drop off waterproof postcards.
The idea started as a way to boost tourism, but quickly became a global curiosity. Visitors buy special postcards on shore, seal them in waterproof envelopes, and then hand-deliver them to the submerged mailbox. Staff members in diving gear collect the mail daily, stamping each card with a unique cancellation before sending it on its way.
Planning a visit? Bring a snorkel or diving mask—the mailbox sits just offshore, and it’s as much an experience as it is a letter drop.

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