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

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

Behind an abandoned storefront is an example of pioneering 1930s gas station architecture.

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

Washington's top-secret Cold War-era doomsday communications tower is located in a small neighborhood park.

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

The most accurate timepiece in the world.

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

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

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

The most decorated dog of World War I is preserved in the Smithsonian.

The country's oldest continually-operated mini golf course lies hidden in plain sight, eclipsed by one of D.C.'s most popular tourist attractions.

A historic ruin just 20 feet away from a busy highway onramp.

A haunting tribute to pioneering photographer Clover Adams.

A derelict bit of transportation infrastructure hidden in the woods.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

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

The only National Monument ever to go missing for nearly 50 years then resurface in a dump.

Also known as the Founding Church of Scientology.

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

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

Part of a WWII submarine is lurking outside the Washington Navy Yard parking lot.

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

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