This grisly headstone doesn’t seem to be resting in peace.

The only Civil War battle in Washington D.C. took place near this highest natural point in the city.

She stares out across six lanes of traffic, clutching a musket and infant with determination.

This free, take-a-book shop seems like a trick but isn't.

You can climb to the summit of Black Mountain, as long as you sign the waiver.

A theme park featuring a replica of Noah's Ark built to the measurements specified in the Bible.

This former maximum-security prison is creepy, sobering, and supposedly haunted.

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

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

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

An exquisite tunnel of cascading flowers.

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

A huge musical instrument played by the ocean.

A 200-year-old bar with a cheeky name claims to have served Edgar Allan Poe his final drink.

The site where Poe "in great distress, and ... in need of immediate assistance" likely died.

The trials and tribulations of marking Poe's grave.

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

Walk a trail through a historic Quaker town that outlawed slavery in 1777 and was a major waypoint on the Underground Railroad.

This suburban house is made of dirt, and almost sparked a revolution in home construction.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

Bizarre Cavern.

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

The park is home to the United States's only still-operating Dutch windmill.