acob’s Well, a perennial artesian spring located about three miles northwest of Wimberley in the Jacob’s Well Natural Area, is a stunning 12-foot-wide limestone pool fed by the Trinity Aquifer The spring marks the headwaters of Cypress Creek and plunges into a submerged cave system that reaches depths of 120–140 feet, making it the second-largest fully submerged cave in Texas Known for its constant 68°F crystal-clear water, Jacob’s Well was once a popular swimming hole and diving site—though cave diving has since been restricted due to safety concerns and several tragic incidents . In recent years, heavy groundwater pumping and recurring droughts have caused the spring to cease flowing multiple times, most recently in 2022, leading to restrictions on swimming to allow the ecosystem to recover Visitors can still explore the 81-acre natural area via scenic trails and join free guided tours that highlight the site’s rich history, geology, and conservation efforts.