Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

The world's only international cryptozoology museum is host to an unrivaled collection of mysterious objects.

A beautiful geyser under environmental threat.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

A dilapidated dock tells the story of Titanic's missed arrival.

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

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

A New York garbage depot holds a secret collection of weird and wonderful refuse.

A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.

Hellam Township is reputed to feature seven remote gates, which when passed through in the right order, open an entrance to hell.

Stroll through a wonderland of stupendous moss-covered trees.

The seamy, underground secrets of Portland's criminal past.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

The only swimming pool listed on the National Register of Historic Places is emptied and refilled each day with naturally filtered water.

A collection of oddities including Dr. Kevorkian's suicide device, the Thanatron.

A semi-scholarly approach to sex.

This Boston medical museum features the skull of the famous medical case of Phineas Gage.

Medical and zoological curiosities for sale.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

This one-room cabin where the young colonel slept during the French and Indian War.

The highest point in Virginia can only be reached by passing through ponies and flowers.

This abandoned mine and power plant was built atop land once given to Revolutionary War soldiers.