Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

Decades before the scandal, this staircase on the river was a literal "water gate."

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

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

A portal into the bricked up canal that runs through the heart of Washington D.C.

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

This church built atop a gas station promises to "equip you for the next stage in your life’s journey."

At 207 feet, one of the world's longest continuous escalators.

This unique historical monument features large concrete spheres designed to resemble fallen stars.

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

Hear, smell, see, taste, and touch history at this immersive Civil War hospital.

This train station inspired the name of a 1970's rock band and provided the backdrop for their album cover.

This Federal-style plantation house was once visited by Abraham Lincoln to meet with generals during the Civil War.

The tomb was guarded by soldiers from both sides of the war, and some left their initials carved in the brick.

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

Long buried under the 20th-century landscape, this lift lock of the Alexandria Canal is the lone remnant of an ambitious early American transportation project.

A superbly preserved example of Georgian residential architecture that was once home to one of the founders of Alexandria, Virginia.

This colonial tavern played host to George Washington, Thomas Jefferson, and other famous early Americans.

This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

Spectacular mineral formations fill these caves, which have been used for everything from smoking meat to stashing illicit liquor.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

One of Belgrade's most beloved animals.

America's first federal monument.

The narrowest house in America is seven feet of pure spite.