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.

This Alaska library may be the only one in the country that allows you to check out pieces of taxidermy.

The first Russian Orthodox church in North America and an Alaskan landmark.

An Alaska livestock farm devotes itself to harvesting wool from creatures that once ran with mammoths and sabertooth tigers.

A rare chance to get up close and personal with a 13-mile ribbon of ice near downtown Juneau.

The king of U.S. high points towers over every other peak on the continent.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

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

Sports history, made in the Arroyo Seco.

This former stomping grounds of the most eminent astronomers of the early 20th century.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

A world-class observatory in the California desert.

Quite simply the largest tree in the world (by volume).

Despite being one of the most photographed vistas in the Rockies these twin peaks are rightfully known as the "Deadly Bells."

Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

The highest bridge in America was built for an almost unnervingly small amount of money.

This "zoo" is a cross between a junkyard and a sculpture garden, featuring animals you won't see anywhere else.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

Holding multiple historical boats and an entire 19th century village, this New England attraction is the largest maritime museum in the world.

A building so large that it has its own weather.