Enormous statue of the Emperor of the Mongols.

A huge communist-era propaganda monument and mural that offers stunning views of the Mongolian capital.

A glacial pothole was once a hideout for a notorious Scottish outlaw.

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

This abandoned island off the Venetian coast has been a radical monastery, a political prison, and a secret Nazi base.

This Italian foot path winds through the mountains via 52 individual tunnels.

Despite centuries of architectural innovation, this French castle is being built like it's the 13th century.

This natural French spring has been turned into a magical grotto by Roman and medieval constructions.

A subterranean shelter remains intact under a busy Paris railway station.

The headless bodies of more than 1,300 guillotined victims of the Reign of Terror are buried here in mass graves.

Indents in the pavement are all that remain from a grisly death machine in Paris.

This is not only one of the oldest collections in Europe, but also possibly the most beautiful.

The last woman executed for witchcraft in Europe is remembered in this Swiss museum.

A communal oasis on Lake Zurich.

Museum dedicated to wax representations of disfiguring diseases.

Featuring Zürich's only authentic 14th-century plague doctor's uniform!

One hundred years ago this small house in downtown Zürich became the birthplace of the Dada movement.

A mythically themed self-built sculpture park.

Extensive private collection of authentic Medieval devices used for human torture and execution.

This lovely little bridge hidden in a Switzerland gorge is essentially a fairytale.

Caves famous for the dragon-slaying saint who lived there.

This secret Swiss fortress is disguised as a harmless pink house, complete with fake windows.

For centuries no one knew there were hundreds of bones and precious artwork hidden beneath this Swiss church.