Take a dip in the world's largest mineral hot springs pool.

A hotel with a rich Wild West history of miners and bootleggers.

The hallowed remains of a 900-year old Ancestral Pueblo great house.

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

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.

Hidden inside this Arizona fast food franchise is an in-depth exhibit on the famed WWII counterintelligence program.

These elusive, isolated rodents evolved into a distinct, locally iconic subspecies.

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

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

This bridge was constructed from the remains of the first Ferris wheel.

This midcentury chapel is a bold architectural statement and a symbol of Indiana's Lutheran heritage.

This large Sitka spruce that appears to be floating in mid-air, has defied logic for years.

A walk through the historic city center, under the streets of Seattle.

After a short-lived attempt to bring America in line with the rest of the world, this road was left in metric.

America's only nuclear missile silo open to the public.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

The unusual burial monument of Arizona's first governor.

Once a year, at exactly 11:11 a.m., this monument comes to life.

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

A replica of the flagpole that gave a frontier town its name.

Ancient pueblos built into the base of a natural canyon wall.

The unusual patterns in this rock formation result from two distinct modes of weathering.

A tunnel with windows, so you don't miss out on the impressive views.