A truly lovely park to relax in, especially with children. It's very well-maintained and features large, shady playgrounds as well as adjacent covered picnic areas.
One small drawback: Swimming in the lake is prohibited. However, there is a nice bathing area, which, although it requires an entrance fee and is only open seasonally. For those feeling sporty, there are public basketball courts where you can shoot some hoops.
You'll need to bring your own food and drinks. About an 8-minute walk away, you can buy a delicious beverage from an espresso machine at the Café Condesa stand.
Once you've finished your coffee, there are restrooms in the park, which have certainly seen better days, but are clean.