You know about the Blue Hole, the headwaters of the San Antonio River, right? Well did you know about the Little Blue Hole?
The Headwaters Sanctuary is 53-acres of spring-filled urban forest with a history going back 12,000 years. The Sanctuary's most prominent feature is the San Antonio Spring, now known as the Blue Hole. Long ago, the Blue Hole was a fountain spring shooting up to 20 feet in the air from a rocky hole in the ground. The Blue Hole was the "source" of the San Antonio River, the mainspring in a field of hundreds of smaller springs that together comprised the headwaters of the San Antonio River. The Little Blue Hole is one of those smaller springs. You can learn much more about the area by checking out the earth cache and the virtual cache at the Blue Hole.