Saint Petersburg was once home to the tram network in the world – Wikipedia says it consisted of 340 kilometres (210 miles) of unduplicated track in the late 1980s, but today has shrunk to around around 200 kilometres of track, following widespread route closures.
When I visited Saint Petersburg finding trams in the ‘city’ proper was difficult, but I did find disused tram tracks crossing the Trinity Bridge (Тро́ицкий мост) over the River Neva.
These tracks continued south from the bridge, skirt the statue at Суворовская площад (Suvorov Square).
Wikipedia has a track map of the Saint Petersburg tram network dated 2013, and it lists the tracks across the River Neva as “Участки трамвайных путей, не используемые для перевозки пассажиров” – tracks not used for the carriage of passengers.
I found a 1982 photo of trams crossing the Trinity Bridge on Wikipedia, by ‘Smiley.toerist’.