When downtown Boston bakes, the Frog Pond on Boston Common flips from winter skating rink to summer spray pool, and half the city’s under-ten crowd seems to end up shrieking through it. The water is only ankle-deep, the sprays run all day in season, and lifeguards keep watch — it’s meant for kids twelve and under, and it’s completely free.

It operates daily through the summer, weather permitting, which makes it the most reliable cool-down in the city core: no reservations, no gear beyond a towel and a change of clothes. The Frog Pond carousel spins nearby for a post-splash treat, and the Common’s lawns and shade trees handle snack breaks. For parents wrangling kids through downtown errands or a Freedom Trail day, it’s the built-in reward stop.