The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

The hidden offices underneath Memorial Bridge have been locked up since 1976.

A brass plaque dedicated to a convicted cannibal hangs in the National Press Club, and that's not even the craziest part of the story.

These recently uncovered walls are all that's left of Washington, D.C's first defense contractor.

A hoard of sky catalogs, astrophysical journals, even the works of Galileo and Copernicus.

Perhaps the most scandalous statue of America's first president.

The only Civil War battle in Washington D.C. took place near this highest natural point in the city.

A three-story tower of books about Abraham Lincoln is one of the more unusual monuments to the president.

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

You could be standing at the site of one of D.C.'s most fatal tragedies and not even know it.

Four bald cypress trees in Lafayette Square, across from the White House, mark the southern edge of a 100,000 year old cypress swamp.

The national park was once a plantation estate.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

A computer bug so primitive it was an actual insect.

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

Largest Roman Catholic church in North America.

There’s a hidden military meme engraved on the World War II Memorial.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.

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

The country's oldest continually-operated mini golf course lies hidden in plain sight, eclipsed by one of D.C.'s most popular tourist attractions.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.