The ruins of an 18th-century mansion that was once named "Mistake" by the man who had it built.

The U.S. government built the million-pound stack of steel during the Space Race.

Proto-CIA agents trained with grenades in the sand traps and fired machine guns from the fairways.

The wooded estate of the Forest Service employee responsible for D.C.’s cherry blossom trees.

The headquarters of the Audubon Naturalist Society is a small slice of heaven for nature lovers.

A total of 14 men held the title of "president" before George Washington—their historical legacies are enshrined in the lobby of a hotel.

A suburban museum tells the story of a historic transportation network and even provides rides in antique trolley cars.

A benevolent, 16-foot-tall river dragon lives on a suburban lawn.

Surrounded by traditional homes, this Tolkien-esque dwelling stands out on a quiet street in suburban Maryland.

Dogs, cats, horses, monkeys, frogs, and fish are laid to rest at the second-oldest pet cemetery in the U.S.

Explore the legends surrounding these mythical sea creatures inside this museum.

Once a thriving business district, this former shopping area is now an urban ghost town in the heart of the city.

Easter in Westminster may be the only time and place to behold Edgar Allen Poe made entirely of Marshmallow Peeps.

George Washington's dentures and Queen Victoria's dental instruments are in the nation’s official museum of the dental profession.

Live data is transmitted from the Atlantic coast to instantly recreate the ocean waves in this fountain at the NOAA headquarters.

A haunting exhibit in a wildlife refuge center highlights threatened species and the conservation efforts needed to save them.

A faded sign from the 1920s remembers Baltimore's resistance toward banning alcohol.

Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.

Once part of a dam servicing an early 19th century grist mill, the tucked-way falls are a tricky-to-find urban oasis.

Despite violent work crews and massive delays this abandoned canal tunnel was built to last into the modern day.

A girls' boarding school inspired by the Chicago World's Fair, once abandoned, now restored to strange and scenic glory.

The ruins of this long-abandoned unsuccessful gold mine can still be found.

An FDR-era tuberculosis sanatorium has stood abandoned in the suburbs of the U.S. capital for over 30 years.

An abandoned church gets a second life as a massive beer hall and event space.