An architect's childhood fantasy treehouse made real.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

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

A beautiful geyser under environmental threat.

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

The location where the iconic movie character declared it was time to go home.

Inside this striking glass building, visitors can see thousands of dinosaur fossils in the positions that nature deposited them more than 150 million years ago.

Thousands of years ago, Indigenous people painted images onto these canyon walls that are still on display today, provocative, mysterious, and enduring reminders of the people who lived here long ago.

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

Erosion and various mineral deposits give this striking canyon its distinct color and soft appearance.

Oddly shaped rock formation, misassociated with a nearby utopian community.

This gallery of prehistoric red ochre art lines the wall of a scenic segment in Utah's San Rafael Swell.

Few things look more out of place than the electric blue ponds in the reddish-brown desert of Utah.

This quiet park's strange sedimentary spires were named after Kodak's color film.

A tunnel with windows, so you don't miss out on the impressive views.

The fifth-longest natural arch in the world, and the longest outside China.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Here, at the "world's longest art gallery," you'll find forty miles of ancient petroglyphs and pictographs.

Ute tour guides have been sharing the ancient dwellings and rock art inside this large park with visitors for more than 40 years.

The narrow mountain road that carves a path between Florence and Victor is tied to ghost towns and ghost stories.

A dangerous narrow-gauge railroad once traced a route through this striking canyon.

This remote Colorado canyon is home to the second-largest collection of natural arches in the world.

A glimpse of a waterfall is reached by a steel catwalk along a slot canyon located in an Ouray city park.