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

Electrical curiosity museum housed in an old transformer station.

Hungarian mummies in beautiful painted coffins.

The remains of a town so thoroughly destroyed by French forces that the citizens simply left.

Abandoned medieval hill town.

This network of conjoined cellars was riddled with traps and supposedly allowed the townspeople to pretend their homes were deserted.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

A lecture hall sink once used by Einstein and other noted physicists is now regarded as a strange science relic.

This small window display is dedicated to the noble carrot.

Inspired by "The Starry Night" this Dutch bike path turns into a glowing work of art each night.

Two gravestones clasp hands over the religious divide.

A beautiful maze marks where three countries meet.

Hiding the longest subterranean river known in the world.

Descend into the tunnels to experience the life of a coal miner.

This sprawling Belgian fort was once thought of as impenetrable but now it is simply an abandoned relic.

Part modern art project, part traditional chapel, this see-through church is only substantial from the right angle.

Somewhere there is a giant who can no longer poop, but now travelers can stay inside his anus.