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

An enormous pink granite batholith, long attributed with spiritual powers by the Tonkawa Indians.

Modern technology and live displays tell the story of the Pacific during WWII for the Internet generation.

Abandoned railroad tunnel is home to a colony of three million Mexican free-tail bats.

A recreated Stonehenge stands in a country field, complete with Easter Island moai heads standing as sentries.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

Three hundred years of preserved Spanish colonial history in San Antonio.

The water in this preserved area spawns vegetation that gives it a deep green color.