A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

Exact replica of the ancient monument, but much, much lighter.

The final resting place of two (or three) presidents, one vampire, and 18,000 Confederate soldiers.

A layered tribute to the work of mosaicist Isaiah Zagar.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

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

The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

The site of the climactic scene from the classic horror film is now a historic landmark.

Bar full of oddities, specimens, artifacts and homages to the great dime museums of the past.

The United States Capitol's former columns still stand.

A museum dedicated to exhibiting remarkable outsider art.

World's first "penitentiary," meant to be humane, drove men insane.

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