This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

Stumps of an Ice Age forest, visible only at low tide.

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

The history of radiation is on safe display at the foot of a radiation science laboratory.

Statue of death tucked in the University of Medicine courtyard.

Egyptian Revival movie palace abandoned for decades and restored in 2013.

A museum of magic with a Sadist past.

Small ship votives hang from the vaulted ceiling of this port-side church with a Latin inscription on the wall.

Two adjoining collections of 19th-20th century physics apparatuses and instruments.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

A curious collection dedicated to human and animal anatomy and pathology.

A cave dug by a man directed by ghosts to find pirate treasure.

At the supposed instruction of Ben Franklin and Socrates, a Spiritualist believer intended to birth a mechanical messiah here.

An overlooked monument to the celebrity gangster who helped put the sin in Sin City.

An eccentric inventor's castle home with its own indoor weather system.

A New England ghost town features a trail of boulders etched with intriguing life lessons.

An 80-year-old house built out of newspapers.

Canada's largest graveyard boasts a lot of noteworthy artifacts as well as its own computerized mapping service.

Grave of the man allegedly responsible for a series of infamous murders in Boston in the 1960s.

Every year, the colorful murals of Montreal get a complete makeover.

Montreal's colorful subway station shows its support of the local LGBT+ community.

One of Canada's oldest museums, the beautiful Redpath has been serving up Natural History and Ethnography since 1882.

This 1967 experiment in modular architecture was designed to be a new model for urban living.