moscow metro
A metro system in Moscow, Russia, known for its grand, often cathedral-like stations. It's a very expansive system, being larger than the Tokyo subway (both Tokyo Metro & Toei Subway) and is one of the deepest subways in the world.
It uses 1,520 mm Russian gauge tracks and 825 volt DC third-rail electrification. The fleet is a mix of old Soviet subway trains as well as hyper-modern ones.