Summer is festival and party time in Amsterdam, and May through August see al-fresco fun kick off in the Vondelpark with a series of concerts at the moon-shaped open-air stage. There are Sunday afternoon jazz sessions plus a program of pop, rock, Latin, classical music, and stand up as well as special shows for kids. Best of all everything is free, although a small donation of around a Euro is requested. Bring a picnic or eat at 't Blauwe Theehuis before the concert starts.