"This cavernous climbing gym is our favorite spot for an alternative work out. With 22,000 square feet of climbing surface, BKB (as regulars know it) is the city's largest and most popular artificial cliff. This is still New York, though, so there are more people than space; we recommend mornings and weekdays to beat the rush. You might bump into Ashima Shiraishi, the 13-year-old bouldering champion who trains here after school. They also offer classes including Adaptive Climbing, for amputees and other unconventional climbers." - Hyperakt