Foam Party (Sant Joan Fiestas)

The town hall esplanade gets hosed down with great mountains of bubbles and let loose to a crowd of squealing children. It runs late afternoon, when the heat has eased a touch but there's still plenty of sun to dry off in, so the timing suits younger ones who'd be flagging by a proper evening event. The foam piles up, kids charge through it, and within minutes everyone is soaked and grinning.

It's a small, local affair tied to the Sant Joan fiestas rather than a big ticketed thing, which is part of the appeal. Bring a change of clothes and a towel, and don't bother with anything you'd mind getting wet. No Spanish or Catalan needed; the language is just shrieking and splashing. Free to turn up, and an easy way for visiting children to fall in with the Muro locals for an hour.