This former mining railroad is one of the best-preserved short lines in North America.

Despite the ever pressing encroachment of urban sprawl this grand New Orleans manse still stands.

A grandiose octagonal home crowned by a large dome stands out among the antebellum mansions.

148 feet long and in the middle of a verdant forest.

Famous for its bio-luminescent inhabitants, known as "Dismalites" .

You'll need cowboy boots to trek to this old-fashioned saloon nestled in a giant natural cave.

Hiding behind a grocery store is a spectacular cavern carved as part of an old limestone quarry.

A bizarre roadside attraction and the first instance of miniature golf in the world.

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

More than five miles of underground passageways.

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

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

The first full-scale tunnel built in America is short but scenic.

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

A natural sandstone bridge hidden in the Sewanee forest.

Located inside a former bread factory, this museum explores a century of transportation history through innovations that were extraordinary or failures—sometimes both.

This park contains one of the largest concentrations of cedar glades, a unique and rare ecosystem.

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

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

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

An abandoned town is hidden in Great Smoky Mountains National Park.

Mile-long cave system near Great Smoky Mountains.

Step back in time on this preserved 1800s farm.

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