Climbing walls have become a hip form of exercise, and there are a growing number of them in Denver on which you can test your perpendicular prowess. (Not included in this list: the wall at the new downtown REI store, more display than challenge.) Yet there's something about scaling an indoor face that violates the spirit of rock climbing. So save your money and head west to the sheer walls off of Route 8 just a few yards east of downtown Morrison. The rocks face south, so handholds are warm most of the year. The routes are short enough that you don't need to haul around ropes and protection (an alert spotter will do), and there are an infinite number of moves to try, from simple to ridiculous. Best of all, you'll get a tan at the same time.