Bosque de San Juan de Aragón

Mexico City's second-largest green space after Chapultepec, this 190-hectare park opened in 1964 and functions as a major ecological refuge in the northern sprawl. The artificial lake draws migratory birds in winter — pelicans, moorhens, and dozens of other species show up seasonally — and biologists on staff lead weekend guided tours through the wetlands.

There's a small zoo, kids' rides, rental bikes and go-carts, picnic zones, and a 5-kilometer running track circling the grounds. Bathrooms cost a few pesos. Open Tuesday through Sunday from 6am to 6pm. Arrive early on weekends — it gets crowded by mid-morning.