The park was alive before the sun had even started to set. Groups of young people glided in on bicycles, bottles clinking in backpacks, laughter spilling ahead like the soundtrack to a spontaneous summer festival. Within minutes, the lawns became a patchwork of circles, bikes stacked nearby. Everywhere I looked, more groups were forming, their numbers swelling across the park.

Then, as if on cue, the circles began to stir. People stood, lined up, and began coordinated movements. I commented to my husband that maybe these were exercise groups, or perhaps line dancers.