Where the U.S. government kept its actual treasure, before Fort Knox.

There just so happens to be a court even higher than the U.S Supreme Court: a basketball court in the building itself.

The fountains of the U.S. Navy Memorial are annually salted with water from the Seven Seas as part of a nautical ritual.

It was once the base for a series of domestic terror attacks.

The famous abolitionist’s preserved estate is one of Washington's finest monuments to its great Black citizens.

A former major munitions plant that has been converted into a sprawling art space.

The 28,000-year-old specimen is remarkably intact.

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

The site of the climactic scene from the classic horror film is now a historic landmark.

‘Bush the old fire dog died of poison July 5th, 1869. RIP.’

A derelict bit of transportation infrastructure hidden in the woods.

They sort through millions of dollars worth of diplomatic gifts on behalf of the government.

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

A pre-Industrial Age iron furnace and the site of a nearly-forgotten piece of Black history.

A cave on the Maryland border where civilians took refuge during the bloodiest battle of the Civil War.

Bizarre Cavern.

One of the only memorials dedicated to journalists who died in combat.

A swimming hole in the historic industrial quarry that supplied the marble for the Baltimore Washington Monument.

A monumental statue of RCA's mascot now sits atop a historical society roof after a life of moving around.

The design of this historic domed church was influenced by Thomas Jefferson and intended as a statement of religious freedom.

A model home in the Medical Examiner's Office in which grisly death scenes are staged to train forensic investigators.

Fiji mermaids, mummified remains, and recreated cryptids are among the morbid oddities at this Maryland museum.