Summer is giving way to fall and, still, visiting a cave is literally and figuratively one of the coolest things to do in South Texas.
First off, there are the "show caves" – those open to the public and, in some cases, tourist attractions.
Natural Bridge, one of the state's biggest caves, offers developed trails and a tour that involves repelling. Visitors above ground can also interact with wildlife.
Cascade is more undeveloped than, say, Natural Bridge. But its quaint charm – and a 100-foot underground waterfall – is alluring.
On the flipside, Cave Without a Name is more educational than touristy. It also occasionally accommodates live acoustic music.
But caving is more than enjoying what lies beneath the Earth's surface. For a group such as Bexar Grotto, a National Speleological Society chapter, caving is about protecting caves and conserving the surrounding land.
Bexar Grotto Chairperson Gregg Williams says the show caves represent a tiny fraction of more than 500 caves known to exist around Bexar County. Some caves are the result of tunneling activities from decades ago.
Adults and youngsters often stumble upon something resembling a cave, many times on private land.
"For all intents and purposes, virtually all of these known caves are on private property or held by non-profits and institutions for research," says Williams.
Typically, groups such as Bexar Grotto may work with the individual or organization caring for a specific cave to set up a time to explore. Otherwise, to paraphrase Boromir from Lord of the Rings, one does not simply find a giant hole in the ground to search inside of.
Robber Baron Cave, off Nacogdoches Road near Alamo Heights, is a project of the Texas Cave Management Association. Caving groups and educational facilities are among the organizations that get to explore it, the longest known cave in the county with nearly a mile of mapped passages.
"It has an interesting history," Williams says. "It's been known since 1886, and it has gone from a speakeasy to being a commercial cave in the `30s. There have been rumors of buried treasure but of course never confirmed."
Bracken Bat Cave, northeast of town, is home to North America's largest colony of Mexican free-tailed bats. Williams was a preteen when he first saw the bats fly out at dusk in search of food.
"Seeing the emergence of 30 to 40 million bats was amazing, life changing," he added.
Government Canyon State Natural Area, which opened to the public in 2005 near Helotes, contains more than 35 caves where exploration opportunities are just starting to get fleshed out.
Groups such as Bexar Grotto are a great, safe way to get involved with caving, Williams says.
"It's a passion," he says.