The heroic sled dog of the 1925 serum run is preserved in taxidermy.

This lovely university observatory continues to sit abandoned since its potential savior was sent to jail for fraud.

This spectacular public market has got meat, fish, vegetables, baked goods, and enough kielbasa for a lifetime.

Deep scars on the earth left by the Ice Age.

Rare recess caves fill this unbelievably beautiful Ohio park.

The massive, incredibly rare instrument is over 11 feet tall with a range so deep it goes lower than humans can hear.

One of the world's largest telescopes, stares into the night sky with two huge mirrors.

Limestone caves with spectacular showcase chambers.

See massive fossils that are over 200 million years old in northeastern Arizona.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

A sharp bend in a dramatic river canyon cut through red rocks.

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

This raised bulls-eye visible from space was the subject of an intense geologic controversy.

The largest island on the great salt lake is home to curious creatures and strange stories.

Come for the speed, leave in love with the desert.

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

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.

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

An antique narrow gauge railway line still running through the Colorado and New Mexico mountains.

A fake mine that was made using real mining techniques which is also used as a community center.

This grand stone tower was dedicated to a famed American humorist almost by coincidence.

The remains of the dam that unleashed a 15-foot wall of water on Denver.

This razorback ridgeline has doubled as a scenic drive since the early 1900s.

This tea house was a hand-built gift from Boulder's sister city in Tajikstan.