Getting there: From MoPac Expressway in Austin head south and take the Davis Lane exit. Head west on Davis Lane and turn left on La Cresada Dr. Turn right on Tiombe Bend and look for the trailhead on the right. Park along the road.
The Hike: Mel Bilich Karst Preserve is a very small natural area designed to protect the numerous karst openings on the property. A karst is a cave opening that provides a quick conduit to an aquifier below. Because of the rapidity with which water can get into the aquifer, bypassing some of the natural filtering done by layers of rock and soil, pollutants that enter the karst opening are more likely to cause environmental damage.
The preserve has no less than 5 karst openings, a pretty good number for such a small area. Each is surrounded by a fence to keep visitors out, and hopefully some trash as well. Each of the caves has a sign indicating the formations' names and some seating areas are available.
The trail surface is crushed granite and is almost perfectly flat. There's a mixture of Sun and
shade and an out and back hike will only yield half a mile and take no more than about 20 minutes.
Dick Nichols Park with its 2 miles of trail is only a few blocks away, so this hike can be taken as part of a package deal. It too has karsts, though not as concentrated and not so near the trail.
This is a really short trail, but the caves are a nifty feature, and the trails are dotted with nice pockets of native landscaping. I combined it ith Dick Nichols and the Latta Greenbelt to make a decent ~3.5 mi hike.