Two geoglyphs that are truly unique to North America.

More than 25 fully functional scale replicas of famous lighthouses dot the shores of Lake Havasu.

The first steel dam in the world and the only one still functional in the United States.

A strenuous, unofficial trail leads to spectacular views in one of America's most remote national monuments.

Red sandstone structures dominate this landscape, which has been inhabited for some 5,000 years.

Petroglyphs, bird watching, and a 100-year-old Ranch in one location.

When it was built in 1929, this historic bridge was the only place to cross the Colorado River for 600 miles.

The final resting place of the businessman-turned-astronomer who helped discover Pluto stands near his observatory.

The remnants of a creative early method of wildfire prevention.

Some 10,000 works of ancient rock art cover these volcanic basalt outcrops near the Gila River.

This comprehensive collection features Native American artifacts dating back centuries.

This huge dam across the Colorado River caused an armed standoff between two U.S. states.

Inside this garden, visitors are offered a glimpse into how inhabitants of the region survived centuries ago.

This ancient trail has claimed the lives of over 2,000 people.

Although now a decaying ruin, this stone cabin's history includes several notable figures.

The largest copper mine in Arizona, this enormous open pit emerges from the hills like an alien landscape.

This oasis-like spring in the Sonoran Desert is home to unique, endangered species.

One of the most extensive and well-preserved collections of dinosaur footprints in North America.

The largest and most well-preserved petroglyph site in the Verde Valley.

The lost ruins of the forgotten ferry lie hidden beneath the silt.

This Old West prison built into the side of a cliff was said to be inescapable.

This reclusive Hopi village in Arizona has been continuously populated longer than anywhere else in America.

The biggest solar telescope in the world helps reveal the secrets of our sun.

The remains of this rugged homestead ranch offer a brief glimpse into a bygone era.