A scientific repository of goiters, boils and other ailments throughout Mexican history.

Gilded heaven for philatelists and architecture freaks, still in full working order despite sitting atop tremulous ground.

Inside a busy metro station, an impressive mural depicts the prehispanic city of Tenochtitlán.

After being lost for nearly a century, this historic bell finally returned home after its mysterious theft.

These faux-cliff dwellings allow visitors to climb around on a replica archaeological site.

The highest paved road in North America winds its way up Mount Blue Sky in Colorado to an altitude of 14,130 feet above sea level.

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

While comics are the main attraction at this megastore, the second floor plays host to an exhibit fit for a museum.

A multiversal transit station located right below a highway interchange.

A focal point of in Denver’s skyline for over a century, inspired by a Venetian basilica.

Overlooking the Colorado Convention Center is this giant sculpture made from thousands of triangles.

This sidewalk tribute honors Colorado's great culinary creation.

A Rocky Mountain city provides a happy ending for a pinto pony and his Brobdingnagian red chair.

A small Wyoming town is home to the state's oldest-operating soda fountain.

The only retired U.S. nuclear missile silo that is open to the public.

This Wyoming town is fascinated by a particular mythical creature.

At the time of its completion, it was the tallest dam in the world.

The high point on the 16th president's eponymous roadway is marked by a massive version of his head.

Around half a million years ago, these magnificent columnar basalt cliffs were formed from cooling lava.

One of the largest collections of wildlife art in the United States, built into the side of a cliff in rural Wyoming.

One of the smallest towns in the United States.

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 first declared National Monument in the United States.