Remnants of a storybook amusement park hidden behind a strip mall.

A relic of FDR's brief foray into utopian urban planning.

A mammoth pair of Civil War artillery guns abandoned out in the forest.

This beautiful stone arch bridge wasn't even expected to stand for one day, but people have been crossing it for centuries.

A lawn full of retired spacecraft on display at one of NASA's first research labs.

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

Fiji mermaids, mummified remains, and recreated cryptids are among the morbid oddities at this Maryland museum.

An eerie, decaying ghost town destined to fade into the forest.

A star fort along the C&O Canal in western Maryland that protected America in three wars.

Giant acorn-shaped 19th century gazebo from which suburban Washingtonians gazed upon the original "silver" spring.

Electronic inventions that resulted in products and systems we use every day are on display in this labor-of-love museum.

Remains of a historic fountain that was mysteriously lost in the demolition of a D.C. traffic circle.

A pre-Industrial Age iron furnace and the site of a nearly-forgotten piece of Black history.

This fort down the Potomac from Washington, D.C. was once the only defensive fort protecting the capital.

The shelves in the back of this thrift store are devoted to saving, not selling, retro tech.

Captain John Smith thought these cliffs were amazing in 1608 but sharks thought so 20 million years before him.

A Civil War Museum with some notable medical antiques.

This abandoned sea fort has become an accidental bird sanctuary.

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

This English-inspired Maryland garden is home to acres of opulent plant life including bushes shaped into an entire fox hunt.

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

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

The remnants of a wooden-hulled fleet built and abandoned in WWI, now home to a thriving ecosystem.

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