There is a wonderful stretch of boardwalk at Mission Bay that is perfect for walking or biking. Although it is known as the “boardwalk” it’s actually a paved concrete path. I went with a few friends on a weekday and rented some rollerblades. We hadn’t skated since high school and we were a bit tentative and wobbly at first. The boardwalk wasn’t too crowded and we were able to roll around and enjoy ourselves for about an hour.