In the Scandinavian Summer, the residents of Copenhagen, Stockholm and Helsinki come out to play. Their beautiful cities come alive: waterways glint in the morning sun, colours glow in the evening light and in between, all sorts of doors open up. There are museums, palaces and designer stores aplenty, and friendly terraces where you can sample unusual dishes. Two days in St Petersburg will also prove irresistible to lovers of art, architecture and history. You’ll marvel at treasures that rival any Renaissance city to the south. Tallinn and Berlin, too, are cities reinvented where vibrant squares and avenues are lined with storied landmarks, fascinating haunts that meld together past, present and future.