Indoor climbing gyms are a great alternative to climbing in the rain, travelling miles to reach decent crags or getting lost in the dark. And the fact that the surroundings are more controlled, and you have dedicated permanently fixed top ropes means you can push the envelope a bit, build skills and try moves you may be a bit nervous about doing on a real crag for the first time. You can also do climbing lessons and buy necessary (and just deeply desirable) gear from the on-site shop.