The ruins of this Dutch castle sit atop a labyrinth of once-secret tunnels and passageways, dating back over 900 years.

Visit the ancient, mysterious Roman catacombs ... in the Netherlands.

This fairy tale forest hides scenes from some of the more obscure and bizarre Western nursery stories.

This beautifully designed star-shaped fort was the premier defense system of the late 1500s.

A Dutch clog company in the town of Zaandam loves the wooden shoes so much it made a museum for them.

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

The attic of a four-century-old canal house hides a clandestine church.

A mysterious lake provides fresh water without any source, somehow restoring itself from atop its mountaintop perch.

Louise Bourgeois' 30-foot-tall steel spider sculpture.

This inexpensive lodging house was once a prison notorious for its inhumane practices.

The remains of a paranoid inventor's hidden workshop lie in beautiful ruins amidst a Canadian park.

Canada's subterranean Cold War museum has doubled as a movie set.

A fake block of cheese remembers a feat of dairy engineering from the Chicago World's Fair.

A Canadian POW for German soldiers during WWII where prisoners hatched an elaborate escape plan.

Legend says that this short Canadian tunnel still holds the dying screams of a girl who burned alive.

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.

A collection of more than 12,000 shoes, displayed in a building shaped like a shoebox.

A unique collection of Science Fiction, Fantasy, and everything in-between.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

One of the largest underground systems runs under Canada's largest urban center.

This Toronto garden collects stares and tchotchkes in equal measure.

This unusual structure may be on its way to becoming a cultural landmark in Toronto.