Line 2 of the Saint Petersburg Metro, also known as Moskovsko-Petrogradskaya Line (Russian: Моско́вско-Петрогра́дская ли́ния) or Blue Line, is a second oldest rapid transit line in Saint Petersburg, Russia, opened in 1961, which connects city centre with the northern and southern districts. It featured the first cross-platform transfer in the USSR. It was also the first metro line in Saint Petersburg to feature a unique platform type that soon became dubbed as "Horizontal Lift".[1]
The line cuts Saint Petersburg on a north-south axis and is generally coloured blue on Metro maps. In 2006, as an extension was opened, it became the longest line on the system.