America's Most Wanted's set resides in this tribute to the history of crime and punishment.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

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

The innocent intentions of this monument are somewhat lost in the sculpture's muscled imagery.

This grisly headstone doesn’t seem to be resting in peace.

This stately mansion, built in 1787 by America's first Secretary of the Navy, is rumored to be one of the most haunted buildings in Washington, DC.

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

The preamble to the U.S. Constitution written entirely from vanity license plates hangs in the Smithsonian museum.

Light bulbs, scrap wood, and tinfoil comprise this homemade throne of the gods.

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

The house where John Wilkes Booth conspired with his co-conspirators.

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

Helen Keller once broke ground on this historic center for the study of technologies to benefit the hearing impaired.

This nine-story building is the oldest standing skyscraper in D.C.

‘Bush the old fire dog died of poison July 5th, 1869. RIP.’

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

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

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

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

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

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

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

People escaping slavery may have hidden inside a corpse vault.

Daily lunch spot for many of Washington, D.C.'s cab drivers.