A labor of love built by local hang-gliding enthusiasts, this ideal launch spot was outlawed by the authorities and has since been largely abandoned.

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

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

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

This abandoned sea fort has become an accidental bird sanctuary.

This Maryland farm is known for its amazing corn mazes and its 30-foot junkbots.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

This landmark cemetery in Boston was created more than 300 years ago.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.

Celebrated as a center of civilization, the remains of the ancient city have been nearly destroyed by greed, egoism, and war.

The stone marker that Mason and Dixon placed at the eastern end of the famous north-south border they surveyed.

This dig site outside D.C. is known for its exceptionally high density of baby dinosaur fossils and dinosaur eggs.

This stately building in Alexandria, Virginia was built by Freemasons to honor one of their most famous members.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

At 207 feet, one of the world's longest continuous escalators.

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

It was once the base for a series of domestic terror attacks.

The oldest continuously operating fish market in the United States.

A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

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

This sandwich shop has a century-old elevator behind a sheet of plexiglass.

Opinions differ as to whether this Arizona tree was actually used as a Wild West jail, but that hasn't stopped the town from capitalizing on it.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.