If you'd like some outdoor excitement, make a day trip to Cowles Mountain. No easy stroll around the block, this hike is great for a mid-vacation work out.
This steep landmass doesn't cost a thing to visit, which is good news if you're watching your money. Cowles Mountain is located in Lake Murray. When you're finished, SDCCU Stadium, Viejas Arena and Santee Lakes are close by and also worth a look.