The Stanford Dish is a 4 mile paved trail that is great for jogging or walking. The trail is open from sunrise to sunset, and gets very popular.
Parking is the biggest problem at the Stanford Dish - on weekends, it can be packed, so it's hard to get in.
The directions here are to the entrance on Junipero Serra Blvd at Stanford Ave (near Page Mill Road).
There's no shade or water on the trail, so bring some water with you in a bottle.