A giant bronze coil of feces is both a tribute to doggie defecation and a reminder to pick it up.

A beautiful geyser under environmental threat.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

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

Climbing this abandoned railway leads to breathtaking vistas of O‘ahu.

These black pillars of volcanic basalt seem to call mountain climbers with an unbreakable siren song.

The world's longest known cave system.

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

Enormous lake at the bottom of a unique cave system.

Kentucky's longest operating jail is now a spooky spot to spend the night.

Visit this playground of waterfalls, caves and sinkholes.

At 135 years old and counting, this historic print shop is heaven for poster nerds and music buffs.

Oregon's unexpected high desert, displaying layers of time in a colorful show.

The first declared National Monument in the United States.

A small section of Boise, Idaho maintains the unique culture and traditions of the Basque people.

The 72-foot giant escaped confinement in a large patch of mulch only to be reburied in the sandy shores of the Potomac River.

One of the oldest living oak trees in the Southeast.

It took years to decode its mysterious messages.

The magic's in the hole!

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

Golden Gate Park's historic collection of plants.

An extensive collection of ancient Egyptian artifacts and mummies.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.