Atop towering Cerro San Cristóbal, there are two municipal pools where many families go to cool off during the summer: Tupahue and Antilén. Conveniently, these all have fabulous views of the city below. However, they do come with a price tag of US$12 for the lower-elevation Tupahue, and US$15 for Antilén, which keeps crowds to manageable levels in January and February.
You want the best view to the city of Santiago plus the Andes Mountains? Go up the San Cristobal and be mesmerized. There are many options to get there: by funicular, by biike, walking or by car / taxi - you choose. Don't forget to drink the typical drink from Chile 'mote con huesillos' to refresh.