Limestone grottoes turns everyday objects into stone.

Longest canal tunnel in the world, abandoned in the 1960s.

A 16th-century horror show built in a lovely Italian garden.

Sail in for a ’dam good slice.

Famed for its pie, this eatery has a hidden tunnel that allowed Catholics to secretly walk to church during the Reformation.

This museum inside Amsterdam's largest cemetery explores how people deal with death.

The former home of a mad diplomat is said to still be marked in bloody, arcane scrawls.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

The world's only museum devoted to the wonders of fluorescence.

Museum preserving torture methods from the past.

Artist Danielle Jacqui decorates nearly every inch of her home inside and out with her work.

A miniature diorama that recounts the brilliant stories of author and filmmaker Marcel Pagnol.

Lady Liberty's original designer installed a little clone in this French fountain.

This medieval chapel is now a shrine to the region's favorite sport.

There is a strange little carving of a person seemingly crushed by a pillar behind the remains of St. Thomas Aquinas.

Now a memorial, this factory was once used as a concentration camp for artists by the Vichy government.

A crumbling island fortress that seems to be covered in a field of stone crosses but is simply incomplete.

For a brief time in 1960s France, families could climb into a tiny submarine and be pulled along an underwater journey.

Sleep in a climate-controlled plastic bubble for the night.

A French library that makes sure its love of books is writ large... giant in fact.

The bizarre home and sculpture garden of an eccentric artist.