The only National Monument ever to go missing for nearly 50 years then resurface in a dump.

A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

A tiny monument to the unsuccessful attempt by Thomas Jefferson to place the prime meridian in Washington.

Before founding the American Red Cross, Clara Barton had a tremendous humanitarian impact by locating thousands of missing soldiers.

This unassuming passageway played a key role in one of the most important events in U.S. history.

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

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

Before Nixon, "watergate" meant canals.

A much-maligned monument to teetotalism.

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

An unassuming, powerful monument north of the U.S. Capitol bears witness to the resilience of Japanese Americans during a time of grave injustice.

A historic ruin just 20 feet away from a busy highway onramp.

Go take a picture with the inventor of the daguerreotype photographic process.

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

This poor little statue is the most vandalized memorial in Washington.

This robust fence in front of a historic Georgetown home is likely made from hundreds of recycled Revolutionary War firearms.

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

A fantastic array of trays and cables once whisked books over to the Capitol at 600 feet per minute.

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

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

A gorgeous mural outside a beloved D.C. restaurant pays homage to famous Black Americans.

The towering figures were created from the cemetery's fallen old-growth trees.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”