The site of a strange super top-secret military experiment during WWII on a remote Canadian lake.

Sitting empty in a lonely Canadian field is a century-old stone bunker sometimes called "One Man's Castle."

What was to be the world's most secure Cold War document vault ended up as just a few shallow caves.

The world's only bushplane museum captures the spirit of the early planes and pilots and their contributions to northern life in Canada.

A sprawling Victorian farm that has been surrounded by a capital city is one of Canada's greatest treasures.

The ruins of a rehabilitation center for World War II vets can be found in the Westminster Ponds Conservation area.

Abandoned for over a century, this chilling train tunnel is now a destination for ghost hunters.

The third version of this tall sailing ship sits, rusted and burnt, in Lake Ontario.

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

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

An abandoned Victorian-era amusement park is rusting away amidst luxury houses.

Lost subway station nestled beneath Toronto's busy commuter line.

Scars of this building's past life as a violent prison still cover its walls.

Beijing's expansive subterranean hiding spot now crumbles away as a tourist destination.

When this test site was abandoned, they didn't even bother to take the rocket with them.

An abandoned water sports stadium that has become a haven for graffiti and decay.

Underneath a chalk hill in France lies what Hitler hoped would be the underground launching base for a devastating new weapon.

This extensive nuclear fallout shelter built from 42 school buses could house 500 people in its tunnels.

This natural sea cave hides a small wonderland of natural turquoise beauty.

A well-preserved network of cavernous tunnels have spent silent centuries removing Toronto's waste.

The secret wartime bunker built on the platforms of an abandoned Tube station.

Pop culture has helped to keep this iconic British building from being destroyed.

A network of concealed passageways lies within a busy London Underground station.

A frozen relic of Seattle's hydroelectric boom is now a teaching facility for future engineers.