Most Beijing parks have something of a mini-amusement park on grounds. The one closest to us where we take the kids when the weather is nice is Zizhuyuan (Purple Bamboo) Park.
Like most activities for kids in Beijing, nothing is free though. We can easily spend $30 or more on one trip, including rides such as boats or the big play area with slides and bouncy castles. There is a carousel and airplanes and a kind of Viking boat. As well as a sand pit and fishing and art area. Look for the “le yuan” at whatever park you visit to keep the kids entertained – or to know where to steer away from to save your money!
Most parks in Beijing also have activities kids will enjoy outside the play area. Zizhuyuan Park has a lake where you can take a leisurely but short boat ride. There are also boats you or the kids can drive yourselves, including ones that shoot water.
In the winter, most Beijing parks convert their lakes into ice rinks (with sleds or skates you can rent). Zizhuyuan Park also sets up a big ice slide, which is like most things – overpriced but fun.