This sanguine boulevard was named after a deadly cowboy bar fight.

See massive fossils that are over 200 million years old in northeastern Arizona.

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 isolated outpost was once the only place to cross the Colorado River for hundreds of miles.

A sharp bend in a dramatic river canyon cut through red rocks.

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

More than a century old, this trading post resides in the Navajo Nation.

An artificial crater field that trained astronauts for lunar exploration.

This 1930s log cabin began as a taxidermy museum but is now a popular country music venue.

A planet-hunting astrograph built in the 1920s to seek out the so-called "Planet X" beyond Uranus.

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

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

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

Originally conceived as part of a proposed Arizona State Capitol building in the 1950s, this structure built in 2004 stands as a monument to the architect's legacy.

Come for the pizza, stay for a performance on the world's largest theater pipe organ.

Brightly colored 30-foot-tall totems light up the desert sky just outside Las Vegas.

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

This immigrant bridge once spanned the Thames but is now a fixture of an Arizona city.

A Saint Nicholas-themed ghost town in the Mojave desert.

All of the 20 occupied houses in this mostly abandoned town feature some curious display of junk art.

A tribute to the statues of Easter Island along Route 66.

Don't blink or you'll miss it.

The remains of a boarding school designed to forcibly assimilate Native American children.

One of the largest, oldest, darkest, quietest motel rooms in the world.