White Nights Festival in Saint Petersburg
White Nights Festival is Saint Petersburg's annual celebration of near-continuous summer daylight, running from late May through mid-July and peaking around the June solstice. The season turns the city into a stage for ballet, opera and open-air concerts, anchored by the Mariinsky Theatre's summer season and the Scarlet Sails celebration for school graduates on the Neva.
Saint Petersburg sits at roughly 59.9 degrees north, close enough to the Arctic Circle that from late May to mid-July the sun never sinks far enough below the horizon for the sky to turn fully dark.