Chaoyang Park is almost unique in allowing people to kick a ball about or picnic on the grass in the summer. Plenty of tree cover as well as some wonderful public sports facilities, including dozens of basketball and football pitches, mean this is a great place to hang out in the warmer months. The amusement park and boating lake are great for outdoor fun and Chaoyang Park is also the venue for many events.
Beijing's largest park also boasts a man-made beach and water park, complete with all the usual suspects (namely, slides) for a day of splashing around. The pool area is huge so even if it's packed on the weekends, there's some room to take a breath. In many ways, the Ocean and Beach Carnival is comparable to Tuanjiehu, but the higher price point pays off in nicer facilities. Entry 90RMB (60RMB after 6pm) Mon-Fri; 140RMB Sat-Sun. Hours 9am-9.30pm.