The entire Shoal Creek Greenbelt which runs for miles along Lamar BLVD is really nice. You can ride a bike from North Austin to South Austin, staying mostly on its trails. The area around Pease Park is especially nice. It really opens up and there is a folfing course and an off leash dog area. Many people jog or play frisbee here. It is also a great place to have a kid’s birthday party, pick up on a game of basketball or just lay on a blanket in the sun.