Hundreds of signs pointing to the birthplaces of current Helsinki residents form stalactites on the ceiling of the cave-like Kamppi metro station.

A subterranean house of worship carved right out of the bedrock.

An abstract monument to a symphonic composer.

On a small island, a replica of a Finnish village from the Iron Age.

A small island dotted with old, historic Finnish buildings.

This church also serves as a lighthouse complete with a beacon.

This irregularly shaped sea fortress has defended not one but three different sovereign states.

These enormous, stern-faced statues greet visitors with lanterns, and sometimes costumes.

This insurance company building reminds customers that witches, bears, and gnomes are out there, best be insured.

The oldest amusement park in the world has been providing a nice spot to have some fun since the 1500s.

This ordinary street was made infamous by a legendary visit from the devil.

The house where a Danish physicist discovered the connection between electricity and magnetism.

Site of the first radio and telephone broadcasting companies in Copenhagen.

Bored potato-guarding Nazis etched their thoughts onto a brick storage building in Copenhagen's Meatpacking District.

This inverted metropolis model is the artist's "revenge" for not being allowed to have a doll house as a kid.

A public display of random paleontology.

This unique architectural wonder is home to luxury apartments.

The largest and best-preserved rotunda in Prague.

An old asylum graveyard that's been abandoned for half a century attracts those seeking a dark thrill.

A historic and beautiful Art Nouveau chamber in a historic railway station.

An Orwellian sculpture with eyeball cameras watches passersby.

A symbol for the opposition to nuclear power around the world.

This bridge's unique architecture honors nautical heritage and encourages self-awareness.

Climb to the top of its spiral spire for spectacular views of Copenhagen.