This hidden jockey “walk of fame” celebrates the winning riders of the Kentucky Derby.

This 19th century mansion façade adorned with immigrant patriotism is a symbol of Louisville’s history.

This modern castle sat empty for decades before a fire inspired its builders to complete its luxury halls.

Where the "World Pinball Champion” is crowned.

The penultimate and final resting places of British General Edward Braddock—minus a few bits and pieces.

The "first cat," "first dog," and even a presidential pygmy hippo all get their due in this museum.

Dedicated to a U.S. Army lieutenant colonel who was also a bird watcher and artist.

An oft-overlooked, magically musical monolith that stands majestically between Arlington Cemetery and the Iwo Jima Memorial.

Though his role as the inventor of baseball may be up for debate, fans still festoon Doubleday's grave with baseballs.

A gift from Scotland to the United States in memory of the 270 lives lost when Pan Am Flight 103 exploded over Lockerbie due to a terrorist bombing.

In what is rumored to be an intentional act of spite, this memorial almost completely obscures the nearby grave of a senior officer.

The naval commander’s proudest moment in battle is memorialized in this unique tomb at Arlington Cemetery.

Born a slave on the Arlington estate, Parks dug the first graves at Arlington National Cemetery, and was buried there, too.

The controversial urban planner who designed Washington, D.C., was buried in Maryland, and can presently be found in Virginia.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

Soldiers were buried next to Lee's house in the center of Arlington Cemetery to dissuade the general from reclaiming his property after the war.

The graveyard holding the remains of George Washington's slaves was forgotten for nearly 200 years.

The rogue roots are gradually consuming some of the historic marble grave markers.

D.C. once had its own tiny rival to the New York Stock Exchange.

During Prohibition, the U.S. Congress had an "official" bootlegger, with his own Capitol Hill office.

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.