The grand marble structure next to the White House is Andrew Carnegie's temple to Pan-American diplomacy.

The word "Watergate" will forever be associated with the infamous scandal in 1972, but this fountain is famous in its own right.

Corn-inthian columns with a uniquely American take on neoclassical architecture.

A line of blue paint marks the route of the inaugural parade.

This statue of one of baseball’s greatest pitchers looks like something out of a sci-fi horror movie.

A promising candidate for the lost rock laid by George Washington was unearthed, but the hunt is still on.

Where you can hail your favorite fictional commanders-in-chief.

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

One of the most influential presidents in U.S. history wanted only this plain, elegant monument as his lasting memorial.

They sort through millions of dollars worth of diplomatic gifts on behalf of the government.

The fountains of the U.S. Navy Memorial are annually salted with water from the Seven Seas as part of a nautical ritual.

An overlooked memorial honoring the local Washington residents who died in World War I.

There just so happens to be a court even higher than the U.S Supreme Court: a basketball court in the building itself.

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

There's an old indoor swimming pool hidden directly underneath the White House Press Briefing Room.

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

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

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.

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

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

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.

One of the largest artillery pieces in the world sits in a Washington D.C. parking lot.