Silver in the hills led to the speedy creation of this boom town and a lack of it saw the town abandoned nearly as quickly.

The last SR-71 ever constructed.

Despite its name, this route in southern Utah offers a heavenly day trip.

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

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

One of the most remarkable caves in all of Iceland was created by a once raging river of lava.

Travel deep inside of Europe's second largest glacier in the world's largest man-made ice cave.

A little-visited waterfall in an otherworldly landscape.

The most powerful waterfall in all of Europe.

Iceland's tribute to its thankless civil servants.

It takes a nine-mile hike to reach these hot springs, but weary hikers are rewarded with stunning views and a warm soak.

All that remains of this once-booming mining town are the ruins of a saloon.

One of the few surviving Panama Canal steam shovels stands outside a tiny Colorado mining museum.

This National Natural Landmark is one of the best examples of a “mass wasting” in the world.

Paleoamericans built these ancient walls high in the Colorado Rockies as part of an extensive hunting system.

A unique arch graces the Dolores River Canyon near the Hanging Flume.

This marker identifies the location where three states converge.

The site of a defunct mill, that once supplied marble for the construction of the Lincoln Memorial.

This old train trestle and collapsed tunnel once allowed the railroad to negotiate the steep slopes of the Colorado Rockies.

This otherwise unremarkable ski town building marks the site of Butch Cassidy's first robbery.

This now-abandoned outcrop is an important Native American spiritual site, overtaken by European settlers and mining pollution.

This 19th century jail was mainly used to incarcerate the drunk and disorderly.

A coal fire has been burning underground here since 1896.

The world's largest sticker ball weighs in at a mighty 231 pounds.