Hamilton Pool Preserve, Austin, Texas, United States

The natural pool and creek are not chemically treated, so water quality is monitored regularly and swimming is occasionally restricted; call ahead to check conditions before your visit. Hamilton Pool is part of the Balcones Cayonlands Preserve and is a protected environment. There are no lifeguards on duty, and drinking water and concessions are not available. Composting toilets and picnic tables are provided near the parking lot. Since Hamilton Pool is a nature preserve, the following rules apply: no fishing, mountain biking, camping, dogs or other pets. Cooking and fires are also not permitted.
History
Prior to the 19th century, Tonkawa and Lipan Apaches lived in the area. In the mid-1860s, Morgan C. Hamilton owned the property now known as Hamilton Pool Preserve. His brother, Andrew Jackson Hamilton, evidently visited the grotto while serving as Texas governor (1865-66). In the 1880s, the Reimer family, immigrants from Germany, bought the property to raise sheep and cattle. Legend has it that their eight-year-old son discovered the collapsed grotto.