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

Explore the flooded remains of a limestone mine in Kentucky.

View Kentucky's beauty and history from the perspective of painter John James Audubon, author and illustrator.

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

An enormous natural sandstone bridge in Kentucky.

Visitors to this arboretum are greeted by three smiling giants crafted from sustainable materials.

Moonbows over Kentucky.

The highest bridge in America was built for an almost unnervingly small amount of money.

When ecosystems collide in the arid Southwest.

The largest self-built castle in the U.S., six decades in the making.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

A spectacular overlook of the Little Grand Canyon of the San Rafael River, a deep sandstone gorge streaked with orange, red and white in a remote, uncrowded part of Utah.

These 100-year-old tunnels in downtown Provo house artists, restaurants, and a few surprises.

This hidden gem in Arizona is truly worth the rugged journey.

These tall, red sandstone pinnacles outside Moab are often forgotten amid their more famous neighbors.

The unusual patterns in this rock formation result from two distinct modes of weathering.

A small oasis not far from downtown Moab.

An Ancestral Puebloan ruin that appears to burst into flames in the sunlight.

One of the world’s largest collections of petroglyphs records 2,000 years of human activity.

Largest collection of mounted dinosaur specimens in the world.

A well-preserved Ancestral Puebloan ruin tucked beneath a desert cliff.

One of the world's oldest and most massive living organisms is a grove of quaking aspens.