This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

Before Nixon, "watergate" meant canals.

At 207 feet, one of the world's longest continuous escalators.

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

This church built atop a gas station promises to "equip you for the next stage in your life’s journey."

This grand gothic brewery has been pumping out suds for over a hundred years.

A small triangle of DC grass is the final resting place of one of Sonny and Cher's songs.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

Obscure Freemasons still live in D.C.’s largest private residence.

Behind an abandoned storefront is an example of pioneering 1930s gas station architecture.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

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

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

A hidden passageway now marks the site of an assassination attempt on Ronald Reagan that some say broke a 140-year-old curse.

There's a crumbling old mansion inside the Smithsonian National Zoo.

When it comes to handsignals (and colonialism) rock always beats scissors.

This forgotten boat elevator was an engineering marvel in its heyday.

The most accurate timepiece in the world.

The bridge's highly-contested plaque (once again) honors Confederate President Jefferson Davis.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

These unusual rooms on wheels are holdovers from the 1960s.

The final resting place of the tragic king and queen of the Jazz Age is tucked away in a small Maryland graveyard.