For the Civil Engineering nerds, the Riverwalk has a north reach that opened in recent years that has a lock system to move the barges upstream. It has some really nice walking / jogging paths and on the right Saturday morning you might find a FIRST Senior Mentor with his relay for life team. SA also has less than year old rent a bike program with bikes parked in stations ready to accept cash or credit for pay by the day/hour rental. Somewhere near the River Center Mall is a Segway self-guided tour of the downtown store. One has to pass a short safety course

I think before they let you out of the shop.