The Gravity Vault, Radnor

Helmed by a team of passionate climbing coaches, all nine of The Gravity Vault's locations surround climbers with more than 15,000-25,000 square feet of climbable terrain. Walls tower past 40 feet, mimicking such natural rock formations as overhangs, keyhole arches, and slabs, and bouldering areas challenge climbers with a latticework of problems that—unlike most of life's—can't simply be solved with dynamite and a pair of roller skates. Visitors can choose from more than 100 top rope routes per location, trusting either the trained staff or a certified fellow climber to man the ropes while they scramble to the summit. When not dangling from a hold or saving lost kittens from a rappel ledge, members can bulk up in the cardiovascular-training area.