Indoor rock gyms are ubiquitous these days. Go to an outdoor gear store, hop on the wall. Private gyms abound. Makes sense, it's simply more expensive and time intensive to climb real deal rock, let alone the training required to safely set a climb.

Taking rock jock egos out of the equation, here are a few differences between indoor and outdoor climbing:

• Indoor climbs are safer. No bad weather -- the environment is controlled. No spiders! No need to sweep away webs.
• Indoor holds are easily spotted, but this can be boring. Outdoor holds are not always obvious.
• Indoor climbing has less distractions (wind, bugs, that thunder in the distance). Do you like the music of the wind or the rock music commonly blaring indoors?
• Indoor climbing is also terrific for technique-watching, and indoor bouldering caves make for a great training ground with a cushy floor in case of a short fall.

Indoor versus outdoor rock climbing should not be an either/or proposition. They both offer tremendous physical and mental benefits. The exhilaration of reaching the highest point you are personally capable of scaling is a rush. Outdoor climbing is my favorite, but I never turn down a chance to climb indoors. One of the wildest indoor climbs I ever experienced was inside these 65 foot silos at Upper Limits in Bloomington, Illinois. Worth a trip.