Went on a Shavuot retreat at Capitol Camps - www.capitolcamps.org - amazing. The camps is built both for kids and adults (they like to call it a retreat center). The mess hall, complete with an installation from www.bigassfans.com complements the lodges, some with a/c, the pool (slides and diving board too!), basketball courts, ropes course, softball fields, lake, hiking trails, tennis courts, and even a roller hockey rink.
Two days of services, friends, food, and pickup games were amazing, even in the 95+ degree heat. And a big props goes to the organizers at www.dcminyan.org.