Parking garage where Bob Woodward met Watergate source "Deep Throat."

Giftshop catering to cryptozoologists and anyone with a sense of humor.

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

Senators used to relax in the nearly forgotten marble tubs now hidden in the U.S. Capitol Building's basement.

The discovery site of the "Capitalsaurus," the official dinosaur of Washington, D.C.

The first presidential bomb shelter was located in an old vault under the Treasury, connected to the White House via tunnel.

Washington's iconic carousel has a nice piece of Civil Rights history.

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

Decades before the scandal, this staircase on the river was a literal "water gate."

An Industrial Revolution-era public work that purified water using nothing but sand.

The walls of the iconic dome are hollow and have a secret stairway.

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

A wondrous old library overlooking the nation's capital.

A historic neighborhood church is reborn as a psychedelic arts collective.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

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.