This sign designates the road that leads to the infamous Area 51.

The site of an underground detonation of a megaton nuclear bomb in the middle of the Mojave Desert.

A picture-perfect town, perfect for blowing up.

The largest man-made crater in the U.S. marks the spot where we once tested mining with nukes.

The contents of this safe survived a 37-kiloton nuclear bomb.

On October 26, 1963, a 12-kiloton nuclear device was detonated here in granite some 1,211 feet below the ground surface.

A facility built in 1992 for an underground nuclear test remains in place today.

This small town Texas cemetery is said to be the burial site of a UFO pilot who crashed in the 1800s.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

Once connected to the outside world by a single train track, this ghost town is looked after by the National Park Service.

This eerily well-preserved coal town was saved from destruction by a Sean Connery movie.

A desert ghost town—occupied for only 12 years—was once home to more than 500 silver mines.

Hidden in the hills of Western Pennsylvania lies one of the best-kept ghost towns in America that you can legally visit.

A total of 14 men held the title of "president" before George Washington—their historical legacies are enshrined in the lobby of a hotel.

An acoustic anomaly with a mysterious cause.

A trash dump made beautiful by nature's power.

This memorial honors thousands of enslaved Africans and their descendants who died in colonial New York.

Deep under Manhattan is the largest construction project in city history. So far, the project has taken the lives of 23 workers, or "a man a mile."

An odd, ancient window that may have once been part of a brutal prison is embedded in the side of New York's Police Plaza.

This small cave in the center of Isla Colon doubles as a sanctuary.

This abandoned hospital is one of the most haunted places in Costa Rica.

The sweetest graveyard in the world is filled with headstones for dearly de-pinted ice cream flavors.

America's post-nuclear-attack chambers of Congress.

An errant donkey ushered in a new era of mining in Nevada.