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

A 300-yard long natural tunnel runs through a ridge deep in the Appalachian Mountains.

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

The remains of a failed attempt at medieval nerdery are hidden deep in the woods of Virginia.

The small cave that housed Tennessee's "first citizen."

This replica of the Greek structure is in the heart of Nashville.

Over a dozen Native American earth mounds dating back over 2,000 years dot this Tennessee archaeological park.

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

The highest point in Tennessee, Clingmans Dome bears witness to the ravages of one type of insect.

This stone memorial pays tribute to a massive shipwreck which was sadly overshadowed by the death of John Wilkes Booth.

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.

The secret city built by the Manhattan Project.

This Tennessee manse was built so opulent that the very utilities doomed it to fail.

Live long and prosper in Tennessee.

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

More than five miles of underground passageways.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

Visit this playground of waterfalls, caves and sinkholes.

Railroad came. People came. Railroad left. Town died.

All that's left of the quintessential "cabin in the woods."

Better known as the "Body Farm," this unique research facility has been studying how human bodies break down since the 1980s.

This structure among the trees was the result of divine inspiration.

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