Olmos Basin Park
Length: 1 mile
One of the best spots for beginner runners, Olmos Basin Park has ample paved tracks and off-road opportunities. Huge Oak trees provide ample shade from the punishing sun, and plenty of soccer and baseball fields mean you're sure to catch a competitive intramural game if you're inclined to stop. The park is always busy, and typically has a police presence -- so if safety is a concern, Olmos Basin is a great option.
Leon Creek Greenway
Length: 14 miles
With 14 miles of trails, Leon Creek Greenway is usually filled with serious runners and cyclists, but with plenty of opportunities to stop and catch a glimpse of water, vegetation, and expansive grassland, the park is also attractive to novice runners and avid hikers. If you're a new runner, don't be discouraged from visiting, just heed this advice: don't run before or after sunset unless you have a head lamp. Cyclists speed through turns in the trails, and it's nearly impossible to see them without some daylight.