For 2 glorious months after school ends, the Frog Pond at the Boston Common turns into a spray pond and becomes the best place to cool off in the city … if you’re 12 or under. The Grand Opening Celebration on Friday, June 24 at 11 am features family-friendly entertainment, music, art, a gala ceremony, and of course, the chance to play in the 30-foot spray at the center of the pond. Lifeguards will be on duty this summer during all open hours.  For more information visit www.friendsofthepublicgarden.org.