I did not find any play grounds in town outside of schools, but I did see many. many children out in public squares doing things with their parents.  Mothers often carried small children strapped in blankets to their chests.  At 7:00pm at night large groups of kids were playing in the main square.  It seemed to me that school had just gotten out at 7:00pm.  The first image is of a boy playing in the fountain after church on Sunday while he and his parents enjoy lunch.  The third image is of a father getting his shoes shined.  The fourth image was taken at night with ambient light.  This three year old boy was having dessert with his mother just after sundown at about 7pm.

These are not great photos (used Photoshop to work around the harsh afternoon light), but I really liked the feel these two photo essays convey about the mood of San Miguel.  Every few blocks in the colonial town you have a church with a plaza which they call the "hardeen" or garden.  In the center of the plaza is a fountain or statue and sometimes a garden.  Around the edges are shade trees and benches.  During the day, people gather here with children to rest while shopping, buy a balloon for a child, or get their shoes shined.  One clever beggar with a scale was charging people to weigh in.  The fountains and pigeons keep the children occupied.  On the sidewalks around the plaza you can find vendors selling drinks, sweets and snacks.  The plaza is lit at night, so these public gathering places are populated with families day and night.