Hamilton Pool Preserve

When it comes to who can build a better swimming pool, nature has outdistanced man hands-down. Take Hamilton Pool, for instance. Centuries of erosion from falling water have formed a gorgeous, green-watered grotto that has become a favorite swimming spot for Austin visitors and residents alike since the 60s. Surrounded by huge slabs of limestone that rest at the water's edge and situated beneath sparkling stalactite crystals that grow from the ceiling high above, Hamilton Pool makes any backyard pool pale in comparison. It's an easy hike to the swimming hole, just don't forget cash - it costs $10 to get in.