Please don’t anchor your boat onto the Department of Defense’s underwater data cables.

The romance of early commercial flight still fills this Art Deco destination.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

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

A much-maligned monument to teetotalism.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

A spectacular tribute to statesman and philanthropist Andrew Mellon.

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

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

A tribute to the pop culture icon overlooks this Washington D.C. intersection.

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

Soldiers were buried next to Lee's house in the center of Arlington Cemetery to dissuade the general from reclaiming his property after the war.

The controversial urban planner who designed Washington, D.C., was buried in Maryland, and can presently be found in Virginia.

Though his role as the inventor of baseball may be up for debate, fans still festoon Doubleday's grave with baseballs.

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

There’s a hidden military meme engraved on the World War II Memorial.

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

On the Fourth of July this area will transform into a Pompeii-like storm of falling embers and ash.

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

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

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

The bank that helped fund the Mexican-American War and the purchase of Alaska met its downfall after helping Augusto Pinochet launder money.

Four bald cypress trees in Lafayette Square, across from the White House, mark the southern edge of a 100,000 year old cypress swamp.

D.C. once had its own tiny rival to the New York Stock Exchange.