This is not the indoor climbing that was trendy around the advent of Y2K. The new rock wall facility is shaped like a cavern and its climbers no longer use ropes or harnesses. Grantville’s recently opened Grotto Climbing & Yoga features a 7,000-square-foot climbing wall with 13,000 handmade holds, and a studio offering 11 types of yoga classes. Designed to replicate the experience of “bouldering” that original climbers did on boulders before attempting a mountain face, Grotto’s walls are lower and climbers enjoy free reign of the ceiling. Instructors teach everything from proper stretching to climbing upside down. After a climb, relax your muscles with yoga. Day passes, $18; monthly memberships start at $69. 4460 Alvarado Canyon Road