If you don’t like the weather in one part of Westcave Preserve, you might like it better in another: Up to a 25-degree difference in temperature has been recorded between the highest area of this beautiful natural habitat, an arid Hill Country scrub, and the lowest, a lush woodland spread across a canyon floor. Because the ecosystem here is so delicate, this 30-acre preserve on the Pedernales River may be entered only by guided tour. Reservations are taken for weekday visits; on weekends, only the first 30 people who show up at the allotted times are allowed in. To get here, take Hwy. 71 to RR 3238, and follow the signs 15 miles to Hamilton Pool, across the Pedernales River Bridge from the preserve.