Touchstone Climbing, San Francisco

The next time you're on the roof of a five-story building, look down at the ground, and you'll get a rough idea of just how high people climb at Touchstone Climbing. The gym's seven locations feature lead walls that rise as high as 50 feet off the ground, though height isn't the only dimension that makes the space feel immense. Each spot has at least 11,000 square feet of climbing terrain, not to mention as much as 3,000 square feet of bouldering.

To prevent newcomers from feeling intimidated by the magnitude of the environment, the gym holds introductory classes. During these sessions, participants learn the basic techniques they'll need if they want to conquer the gym's crack systems and boulder problems. The classes are also an opportunity for students to scope out the terrain features at each location, such as Diablo Rock Gym's steep prow, which juts out crookedly like a thumbs up from a dizzy ballerina. While they're at it, the visitors might notice something else: the social nature of the gym. As the San Francisco Chronicle recounts, the fact that lead climbs require two people means that climbers are constantly asking around for new partners and chatting back and forth as they ascend.

Each location also boasts a weight room, cardio machines, and a studio space for everything from yoga to spinning to core classes.