Santiago has several swimming pools (both indoor and outdoor), where you can swim, play and sunbathe. There are also several spas and hydrotherapy centres, which are relaxing and amusing at the same time.
But if you also want to enjoy nature, there are refreshing, fully-equipped river swimming areas only a few minutes away from the city. There are also beaches along the coast, with calm waters and fine sand, which are perfect for children and the closest are just over 30 minutes away.