At St. Mark’s, fun and learning intermingle, while swimming is fundamental. Campers ages 4 to teen can concentrate on age-appropriate sports, arts, and sciences. Little ones fill their days with classes such as tumbling and cooking. Older campers can practice fencing or study DNA, drama, sewing, karate, rocketry, and the list goes on. Even the most discriminating kids should find something to keep themselves intrigued. Weeklong, half-day camps start at $130; and day camps start at $260.