This is the second time we've visited here. A bit of a drive from San Antonio, not terribly far from Austin. This small preserve offers a nice escape from the city. Swimming is an option in the natural pool here but as there was a hard rain a couple days before our visit, swimming was ill-advised by the park ranger this day (large amount of run off increased the bacteria levels). There isn't much a lot of room for many cars or people so the park rangers limit the cars allowed in. Cash or local check only for a $10/car fee. The pool itself is a short walk down some rocky terrain so wear good shoes. Bathrooms only available near parking.