The elevator that makes it possible to fly American flags in bulk over the U.S. Capitol

Before Metro, Washington had a robust streetcar network—and you see the remains of this infrastructure if you know where to look.

A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

Washington's top-secret Cold War-era doomsday communications tower is located in a small neighborhood park.

The institution is sitting on a goldmine of 21,000 paints, varnishes, pigments, and primers preserved for posterity.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

During the Industrial Revolution this “Temple of Invention” was full of intricate miniature machines and gadgets.

Government testing at the asylum briefly explored using marijuana as a "truth serum" on Nazi prisoners of war.

Journey through vintage Americana inside this small Massachusetts shop.

Retirement home where the actress who played the Wicked Witch of the West passed away.

A fascinating and enormous collection of natural history exhibits stained by a dark colonial legacy.

A gas station and a state sign commemorating the most famous claims of extraterrestrial abduction.

Even Henry David Thoreau found this glacial pothole irresistible.

An abandoned tuberculosis hospital moulders on into an uncertain future.

Ruins of a historic medical facility sits eerily by the water.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

Site of the first pathological and bacteriological research facility in the United States.

A crumbling hospital from the 1850s on Roosevelt Island.

Now abandoned, the first public health hospital in the U.S. saw more than one million immigrants from around the world.

Hunt for buried treasure in Nova Scotia.

Buried beneath an unassuming Gotland farm was the largest collection of Viking silver, mostly of Islamic origin.

Sandstone rock formations that look like they belong on the cover of a progressive rock album.

An abandoned facility that has become a place of ritualistic satanic worship, or so rumor has it.

The remains of this hell for leather wild west town can still be found in the Arizona desert.