I went to away-camp in Maine for 7 weeks at a stretch during two summers (aged 12 and 13, I think). I was relieved to get out of my parents' house; it didn't matter that the girls hated me, it was still a relief.
While the girls were almost uniformly rich, WASP bitches-in-training, the setting was spectacular and the activities were great. I learned how to canoe, sail and ride horseback. Some of the counselors were wonderful women. I still have a soft spot for the place.
http://www.alfordlakecamp.com/
ETA: Holy crap, it was expensive -- $7500 per summer!