A railroad tunnel that, upon its completion, was considered one of the engineering marvels of the modern world.

A small Richmond island dotted with the remnants of hundreds of years of history.

The trials and tribulations of marking Poe's grave.

It's easy to see why this eclectic architectural wonder has been dubbed the "Spaceship House."

The official atomic museum of the United States explores the explosive and productive history of a much maligned energy source.

Funhouse of found art and participatory sculpture.

The fungus-shaped vintage gas station has served multiple purposes over its lifetime, and now serves ice cream.

The only tennis court that falls under the jurisdiction of the central bank.

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

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

Look closely and you’ll notice that the color changes a third of the way up the tower.

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

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

A building shaped like the Army Corps of Engineers logo, because why not?

This forgotten boat elevator was an engineering marvel in its heyday.

Before Nixon, "watergate" meant canals.

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

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

The span is crooked and made from two older recycled bridges.

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

The privately owned cemetery that holds room for Washington's finest when they step down from life.

The most accurate timepiece in the world.

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

The site of the climactic scene from the classic horror film is now a historic landmark.