Historic buildings are pictures during the blue hour in Saint Petersburg, Russia, 18 October 2012. The entire historic city centre with 2,300 listed buildings is a UNESCO world heritage site. Photo: JENS BUETTNER

- Image ID: D20G45
dpa picture alliance / Alamy Stock Photo
Image ID: D20G45
Historic buildings are pictures during the blue hour in Saint Petersburg, Russia, 18 October 2012. The entire historic city centre with 2,300 listed buildings is a UNESCO world heritage site. Photo: JENS BUETTNER