Jacob's Well is a perennial karstic spring in the Texas Hill Country flowing from the bed of Cypress Creek, located northwest of Wimberley, Texas. The twelve foot (four meter) diameter mouth of the spring serves as a popular swimming spot for the local land owners whose properties adjoin Cypress Creek. Jacob's Well is considered a dangerous underwater cave for novice or non-cave trained SCUBA divers, with a dozen divers having died in the system.