In the woods of New Jersey lie the ruins of a munitions village abandoned after World War I and the remnants of a 1920s wooden racetrack.

Scotland's first Masonic lodge may also be the oldest in the world.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

The remains of a failed attempt at medieval nerdery are hidden deep in the woods of Virginia.

This large, circular tomb is the final resting place of the first emperor of Rome.

This floating garden in the sky is straight out of a fairy tale, but the real thing is nothing short of magical.

Once the most densely populated place in the world, this island is now a ghost town.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

Designed as a labyrinth, this subterranean prison was crafted without bars or doors.

The stunningly blue waters of these beautiful caves also have a violent past.

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

Countless grotesque faces stare out from this eerie Prague art wall.

The main gates have been locked since 1745 and will remain so until the Stuart Dynasty returns to the throne.

This magnificent, quirky home sits atop a literal gold mine in the middle of the Nevada desert.

An architect transformed this abandoned cement factory into his castle-like workshop.

A rugged lava field dotted with molds of the ancient pines that were growing when the volcano erupted.

On the Oregon coast there is a natural hole that seems to be draining the sea.

Two massive rock outcroppings on the Oregon coastline.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

This lake in the Cascades lives up to its name, disappearing down a hole every spring.

A volcanic fissure over two miles long and up to 70 feet deep.

Massive crater in central Oregon.

The longest continuous lava tube in Oregon.

A legal loophole makes it possible to get away with murder within this 50-square-mile section of Yellowstone.