Zilker Park and Preserve is the crown jewel of Austin's park system. The park is on the south side of Lady Bird Lake, off of Barton Springs Road between Mopac and Robert E. Lee.

Zilker contains Barton Springs Pool - Austin's spring-fed natural swimming pool that stays around 68 degrees year round, and the closest thing Austin has to a beach. Open early in the mornings, Barton Springs changes character as the day rolls around. Around sunrise, the pool is filled with serious swimmers doing laps in the pool - triathletes in wetsuits or swimmers who have been swimming in Barton Springs every day for years. Later in the day, the pool gets too crowded for serious swimming, and you will see more kids and young adults sunbathing, playing in the water, or cannonballing in off the diving board.

Zilker Preserve is on the other side of Mopac from Zilker Park, and two miles of trails wind through the preserve through to the Austin Nature and Science Center. These trails are not ideal for hiking and running, as they aren't well marked and don't flow well at all.

The Barton Creek greenbelt trail starts in Zilker Park and goes 7 miles to the Hill of Life along Barton Creek. This trailhead can be very busy, but there are restrooms and water fountains at Barton Springs. Also if you start here, you can cool off in Barton Springs afterward.

In addition to Barton Springs and the trail systems, Zilker contains a disc golf course that sees a lot of use, the newer and not very heavily used 1-mile Zilker Loop Trail (mostly sidewalk), a couple of playgrounds, and a lot of picnic areas.