Only known mainland rookery of the threatened Stellar sea lion.

Fifty years after a “blast blasted blubber beyond all believable bounds,” this idyllic natural area commemorates the carnage.

A cave's rare beauty held a cavernous secret hidden underground.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

A blacklight journey through a celestial art exhibit.

A museum dedicated to the alleged Roswell Incident.

Inside this small museum resides a strange mix of miniature collections passed down over time.

This fast-food outlet is the only space and UFO-themed McDonalds in the world.

This 19th-century religious artwork was once highly controversial—because it was donated to the church by a divorcee.

This soaring sculpture and Sioux Falls landmark represents the leap of faith taken to make one's dreams come true.

More than 7,000 gallons of water pour over these cascading red quartzite waterfalls every second.

Three legendary, living albino buffalo roaming their pastures for all to see.

This municipal park along the Missouri River honors the galley central to the Lewis & Clark Expedition with a replica ship and sculptures.

The world's largest Holstein cow.

One man's quest to save his town with a trail of record-breaking sculptures.

This memorial pyramid marker honors one of the United States Government's first official camel riders.

These markers are used to determine the ground stability of the Strip.

Formerly the world's largest, this Willy Wonka-esque contraption runs 24/7.

Las Vegas's very own 40-foot-tall fire-spewing praying mantis.

One of the "twins" in these falls on the Snake River was sacrificed for hydropower generation in the 1930s.

These falls, sometimes called the "Niagara of the West," still put on a good show at the right time of year.

Where the famed daredevil attempted to launch himself across a canyon in a custom-built rocket.

The only bridge in the United States where BASE jumping is legal without a permit year-round.

An impressive waterfall nestled in the cliffs of Idaho's Snake River Canyon.