The only road through the heart of Glacier National Park.

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.

The last physical evidence of the Lewis and Clark trail is one of their autographs etched into this giant rock.

The drama of nature in full effect in this Nevada State Park.

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

A dramatic, 360-degree recreation of Pickett's Charge in the Civil War.

A labor of love built by local hang-gliding enthusiasts, this ideal launch spot was outlawed by the authorities and has since been largely abandoned.

Bizarre Cavern.

European castle ruins in an American state park are actually the product of death and grief.

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

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

Moonbows over Kentucky.

In the St. Francois Mountains in the Ozarks at 1,772 feet above sea level, Taum Sauk Mountain is the highest (and possibly oldest) peak in Missouri.

Giant granite rocks standing end-to-end like a train of circus elephants.

The Old Courthouse takes visitors on a captivating trip through St. Louis' timeline.

The world's longest known cave system.

You have to love a museum with a truly dedicated focus. A focus on Superman, for example.

River pirates, murderous bandits, and serial killers used this Illinois cave as their debauched hideout.

You thought Santa Claus didn't exist, but it turns out you were wrong.

The farm where one of America's greatest leaders was raised is now a well-appointed landmark.

This open air cathedral invites all faiths to worship under the only roof big enough to fit them all: the sky.