White Nights: St. Petersburg, Russia
Credit: KIRILL KUDRYAVTSEV / AFP / Getty Images

St. Petersburg lies just outside the Arctic Circle, meaning balmy summer nights remain illuminated by a sun that just won't set during a period referred to as White Nights. This summer celebration is capped off by Scarlet Sails, a spectacle that draws a crowd of millions along the Neva River for pirates, fireworks and a towering ship with the deep red sails that give the event its name. Be sure to wear comfortable shoes. The size of the massive crowd means early birds are rewarded with the best views, but trying to leave can be a chore. If you want to take part in Russia's largest celebration, you've got to be in it for the long haul.