Mankind’s feeble climbing skills and inability to digest delicious tin cans are two ways in which evolution left humans inferior to goats. Channel an inner mountain goat with today’s Groupon: for $19, you get two day-passes with rental gear an introductory climbing class at North Wall Rock Climbing (up to a $52 value), located in Crystal Lake.

At North Wall Rock Climbing, rock scramblers ascend the gym’s more than 15 top-rope stations and a bouldering area with challenging terrain. Seasoned instructors teach rock climbing basics in a Climbing 101 introductory class (a $40 value), familiarizing students with basic procedures, equipment, and how to make guttural, Sylvester Stallone–esque noises. The class lasts less than an hour, and newly anointed scalers can stay for at least two hours post-course to hone and refine ascension technique. The intro class includes instruction, day pass, and equipment rental, including shoes.

Burgeoning ascenders could also exchange this deal for two day passes (a $10 each value for students, $12 value on weekdays, $14 value on weekends), plus rental gear ($12 per day), for an all-day climb-a-thon. Crawl up the gym’s numerous, ever-changing routes, or try your grip on the bouldering area’s upper and lower caves with varied terrain, including slab, vertical, and overhanging. North Wall challenges veteran climbers with a steep back wall for highball bouldering, three cracks with hand jams, and a 30-foot-plus roof for clip draws that leave mounters upside-down, ideal for painting the top of one's Simon & Garfunkel parade floats.

North Wall’s fully stocked pro shop touts climbing books and DVDs to help disciples master the craft, as well as vegan cookies for fueling complex wall choreography.