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

Bizarre Cavern.

Spectacular mineral formations fill these caves, which have been used for everything from smoking meat to stashing illicit liquor.

The highest point in Maryland is only accessible by hiking through another state.

Behold the rickety wooden glory of the world's oldest operating roller coaster.

Steepest flood safety railway in the entire world.

A giant time capsule not scheduled to be cored until 2040.

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

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

The antique hotel still has a jail in the basement, though the cockfighting ring is long gone.

Maryland's first (and last standing) toll house on America's first federal road established the state as the "Gateway to the West."

This one-room cabin where the young colonel slept during the French and Indian War.

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

An abandoned stretch of highway, deteriorating next to the operational one.

This titanic java kettle is one of the many kitschy landmarks located along America's OTHER famous highway.

This Art Deco service station has been providing tune-ups and turning heads for close to a century.

A dozen U.S. presidents have stayed at the historic resort, which was known as James Buchanan’s “Summer White House” from 1857-1861.

Pennsylvania's highest point is spotted with boulders which were pushed to the surface by nothing but cold.

This abandoned asylum was once a state of the art facility before devolving into one of the most deadly mental institutions in American history.