Softball and cookouts are all well and good, but now there's an entirely new sort of activity available in New York City parks: A so-called "Challenge Course," also sometimes called Project Adventure, or just a ropes course. Parks commissioner Adrian Benepe is unveiling the course today in Queens' Alley Pond Park; with a climbing wall, a 60-foot-high pulley called a "flying squirrel," and all manner of other things to scale, vault, and balance upon while perched high in the air, it's the biggest such installation in the Northeast. Summer-camp groups will get the course Mondays through Wednesdays; on Sundays it's open to the public. Other times, the city hopes to rent it to groups and corporations for team-building exercises. Benepe views it as yet another new tool for fighting childhood obesity. "We now have two mountain-biking courses, half a dozen skate parks, and an outdoor Velodrome in Queens, and our park rangers run canoeing on the Bronx River," he boasts. It's like some sort of weird, modern-era pentathlon. —Alec Appelbaum