South Florida's topography does not lend itself to extreme sports. It's flat, flat, flat. But don't give up. This 12,000-square-foot Kendall warehouse has been converted into an air-conditioned climbers' paradise. The faux cliffs, boulders, and rock ledges are arranged into everything from a novice, 30-foot climb to an ascent that requires hanging upside down from the 45-foot-high ceiling. Safety ropes and mats help prevent serious injury, but not that next-day burning sensation in the muscles. The entrance fee is $12. Rookies are required to take a $30 training class. X-TREME is open seven days a week. On weekdays you can start suffering at 3:00 p.m. On weekends doors open at 10:00 a.m. Why drive to the suburbs to scale a fake mountain? Because it's there.