Natural catch-basin rocks covered in thousands of drawings spanning many millennia.

Steep canyon walls hide a forested oasis in the West Texas desert.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Campus tradition says couples who walk beneath this enormous oak will stay together forever.

Decades of discarded bottle caps line this alleyway, a fixture of Texas A&M.

The second largest roadrunner in the world stands 11 feet tall in his West Texas town.

The tree is thought to be the oldest oak in Texas and was once crowned state champion for its monumental size.

An abandoned quicksilver mining town surrounded by the Big Bend parks.

A Texas cave network is home to some of the world's most spectacular-looking and bizarrely named mineral formations.

Twenty-seven massive radio antennas on the high plains of New Mexico search for life on other planets.

These ruins of a pre-Columbian cliff village are among the most beautiful and well preserved in New Mexico.

Golden Gate Park's historic collection of plants.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

Beer lover's can-covered house.

At the "Garage Mahal" in Houston, car culture is about more than just driving.

A wall of chewing gum moonlights as collective art.

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