Smooth basaltic rocks tell a tale of ancient glacial waterfalls.

A statue representing a lost Roman profession that was vandalized for centuries.

This castle was once the home of one of the most powerful women of the Renaissance.

Roman politician Herodes Atticus built this nymphaeum to honor his wife, whom he may have murdered.

An abandoned facility that has become a place of ritualistic satanic worship, or so rumor has it.

A trove of ridiculously valuable prints and manuscripts under one roof.

This one-of-a-kind archeological site is home to strange prehistoric ruins, the original use of which is still a mystery.

The deadliest diving spot in the world is also a stunning geological marvel.

The secret medieval communication system will whisk your words above the noise of the crowd.

Access to this hidden site of a 14th-century mass suicide is prohibited, unless it is to pray for the dead.

This mysterious medieval grotto holds a grid of sacred wells of unknown purpose.

A plaque marks the spot where the saint was shoved off the Charles Bridge and into the river.

This park pays homage to the region's rich industrial history of brick making.

Jail from the 19th century that was built by inmates.

A 30-acre garden inspired by the principles of modern physics.

A creepy statue of a hooded ghost hauls itself up from the water in a historic Lithuanian city.

A free, public museum dedicated to the fascinating science of sight.

The unusual patterns in this rock formation result from two distinct modes of weathering.

This seaside Italian village doesn't just look Escher-esque, it actually inspired the mind-bending artist.

Ancient rock-hewn town that witnessed key events of Georgian history.

This memorial park stands on the site of one of the largest mass executions of the Second World War.

This industrial area was the dumping ground for massive amounts of trash, some of which washes up as tiny bits of sea glass.

A cursed torii gate still stands on the edge of Haneda Airport, decades after its shrine's relocation.

The 19th-century ruins hide deep in an overgrown forest.