Possibly the world's largest hourglass only needs to be reset every New Year's Eve.

Rent out a glass igloo to watch the Northern Lights like you live in the future.

Venice's island of the dead.

2300-year-old Roman road connecting the empire.

Mummified monks and the accidentally interred, in a 17th-century crypt.

Bohemian paradise covered in majestic forests.

Two monstrous faces loom over a village in Czechia.

An abandoned whaling station on an active volcano offers hot springs in Antarctica, surrounded by ruined giants of industry.

Once the home of a hermetic monk, this cave now houses a small church.

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

Better known as the "Body Farm," this unique research facility has been studying how human bodies break down since the 1980s.

An underground city of salt.

The world's brightest bioluminescent bay.

Enormous lake at the bottom of a unique cave system.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

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

Two stunning 17th-century libraries and a cabinet of curiosities.