Just outside the bustle of Austin, Hamilton Pool Preserve sits hidden by lush vegetation. Formed by thousands of years of water erosion, this pool, grotto, and canyon features a 50-foot waterfall that spills over limestone outcroppings. Depending on precipitation, the stream can reduce to a slow trickle but is never dry.

Remains found in the area date back 8,000 years and have led researchers to believe it was originally used as a shelter by its ancient inhabitants. Named in the 1880s for its first owner, Morgan C. Hamilton, who was a brother to Texas governor Andrew Hamilton, the land was originally grazing land for livestock. According to legend, Hamilton's eight-year-old son discovered the collapsed grotto.

Ranchers began to use Hamilton Pool for recreation, and today, the preserve hosts 75,000 annual visitors.

When to go: The best time to visit Hamilton Pool is in July and August, when it's warm enough to swim, and free of the bacteria that comes with heavy rain. Try to arrive at 9am, when the watering hole opens, because the Preserve often reaches capacity early in the day. Long lines – sometimes up to two hours long – are not uncommon. Note: There are no lifeguards and swimming is at your own risk. The preserve stays open until 6pm.

What to do: Besides swimming, Hamilton Pool Preserve offers guided tours by appointment from October through April. Observe plant ecosystems and a variety of wildlife on the quarter-mile trail to the natural pool. If you're hiking, wear sturdy shoes to balance on the rock steps that descend into the canyon. Also bring a water bottle and some snacks. Concessions are not available but picnic tables abound.