One of the oldest active carousels in the country—but it might be missed by all but the keenest-eyed boardwalk strollers.

The elevator hidden in a smokestack on Roosevelt's yacht now serves as a monument to the former president.

FDR's Art Deco hospital tower was hopelessly inefficient.

This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

This historic lighthouse was well known for the large number of women who served as its keeper.

The tallest The Church of Jesus Christ of Latter-day Saints temple in the world soars above the Beltway.

Baltimore's classic clock tower was once topped by a rotating, 20-ton medicine bottle.

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

Historic home of America's sweetheart sharpshooter, Annie Oakley.

This 1830s store is believed to be the site of Harriet Tubman's first stand.

Rediscovered after a century, the father of the American Navy was reinterred in something dredged up from Davy Jones' Locker.

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

The design of this historic domed church was influenced by Thomas Jefferson and intended as a statement of religious freedom.

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

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

Built by the patriotic residents of Boonsboro in a single day.

This abandoned sea fort has become an accidental bird sanctuary.

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.

The land is home to swimming ponies and a legendary 18th-century treasure.

A local farm's collection of unusual structures from a now defunct storybook amusement park.

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

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

This museum explores the grim reality of life in the earliest British colonies in America.