Absolutely correct as the above posters informed.
The activites depends on the age of your kids,
Small ones - Parents usually go to Plaza de los Bomberos, and bring bikes etc. It is right in town.
Bigger ones - There is all that HB stated. Also ballet, English, drums etc etc.
To be part of a sport club is not expensive at all, around 100 pesos/month and sometimes less, 200 per 1/2 year.
Also for teens, there is game clubs, cinemas, gocart etc etc