Take the Red Line north, heading out of St Petersburg, and you’ll eventually reach Courage Square on the city’s outskirts (if you pass Polytechnic you’ve gone too far). From there, it’s a brisk 20-minute walk along the birch-lined Avenue of the Unvanquished to Piskaryovskoye cemetery, home to some 186 mass graves and almost half a million civilians and soldiers who died during the 900-day siege of the ‘hero city’ during the second world war – or, as it’s known to Russians, the Great Patriotic War.