During the 19th-century, this park was a vital trading fort.

This scented city oasis was a labor of love.

A former Oz-themed attraction that has fallen into disrepair, but still holds some of the original magic.

Gnarled canopies of pink and purple wildflowers arch over the trail to the summit.

This maze-like slot canyon is a unique gem within an already fascinating geological area.

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

Once connected to the outside world by a single train track, this ghost town is looked after by the National Park Service.

Stay at this storybook estate, featuring Sir Henry Hudson Kitson's masterpiece "Gingerbread House."

This stunning home looks like it belongs in medieval Europe, not North Carolina.

America's post-nuclear-attack chambers of Congress.

This former fire tower is now a rustic observatory that offers amazing views of eagles, hawks, and the Appalachian Mountains.

Mystery surrounds a famous marshal of Napoleon's army.

An enormous goose sits atop this nest-shaped home.

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

The world's longest known cave system.

Symbolic attempt to overcome the issues of life.

This Kansas City studio was home to Walt Disney's first animation business.

The "World's Largest Underground Business Complex," a 55,000,000-square-foot city underneath Missouri.

Jule Körner's house full of bizarre architectural details.

Ruins of an American Civil War iron forge still survive today.

This woodland architectural installation acts as a camera obscura for the heavens.

Now nearly abandoned, Kaskaskia was once the capital of Illinois and one of the most important towns on the upper Mississippi.

This wooded grove of beautiful hand-built stone grottos is a hidden gem within a shuttered Franciscan monastery.

400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.