One of the deepest blue holes in the world.

This cavernous swimming spot doubles as a home to the largest known colony of bats in Central Asia.

A fiery crater has been burning in the Karakum Desert since 1971.

This historic stone bridge has an entire neighborhood clinging to its sides.

Australian museum dedicated to human health and lack thereof.

One of the oldest medical collections in Europe focusing on rare surgical instruments.

A 19th century artistocrat's mansion, turned into a library, hidden in a modern library.

A swing to dangle you off the very edge.

Sweden's first nuclear reactor, R1, can be visited 25 meters underground.

A dormant lightning machine equal to all the power in Russia.

The largest collection of medicinal plants in Australia is also home to a witch who will show you how to use them.

Located in the house where Gustave Flaubert was born, this odd museum has more to do with medical grotesquery than the Western novel.

The site where one of the most famous poems of World War I was composed is preserved to honor the legacy of the work.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

The largest catacomb system in the world.