Mysterious ancient boulder carved with petroglyphs in the mountains of Western North Carolina.

One man’s religious convictions led him to build this stone castle meant to withstand an apocalypse.

The remains of the iconic train crash from the movie The Fugitive can still be found rusting along the Great Smoky Railroad.

These early tent-shaped grave coverings are unique to Appalachia.

The scant remains of this flooded historic village can be explored in one of the most remote areas of the Great Smokies.

This 5-by-6-foot wooden hut is the smallest historic post office in the U.S.

One man has spent decades faithfully constructing this unique brick and cinderblock castle.

Abandoned for 60 years, this submerged bridge was completely forgotten until the lake was drained.

Visit this playground of waterfalls, caves and sinkholes.

Labor provided by Great Depression-era programs restored these 25,000 acres in Tennessee.

One of the world’s largest and deepest freshwater springs, where mastodons once roamed.

View rare birds and interact with lemurs at this nonprofit run entirely by volunteers.

An abandoned bait shop with a front lot filled with storage boxes.

Whimsical bronze sculptures of smiling coins and houses await visitors to this park.

A local landmark with generations of spraypainted messages, and more being added each day.

Built in 1785, this residence is the oldest stone house in Georgia.

All you ever needed or wanted to know about America's favorite whiskey, but not a drop to drink.

This historic general store still operates much as it did in the late 1800s.

This funicular railway rumbles along for a mile up the nearly vertical face of Chattanooga’s Lookout Mountain.

The ruins of a creative scholar's fantastical unfinished sanctuary act as his massive gravestone.

Working compound meant to allow visitors to reclaim the values and traditions of the past.

This now-deactivated naval base defended the Florida coast for centuries.

This large cave is a summer home to thousands of bats and has a rich history dating back to prehistoric times.

An unusual art exhibition in a suburban yard is designed to awaken the souls of those flowing by.