I took the Trans-Siberian Railroad though Russia and into Mongolia when I was 17. 1 took 1 bus and 2 overnight trains from the north of Sweden to get to the starting point in Moscow, and then spent 5 days on that one train before it reached Mongolia.

They stopped for about 20 minutes at each station, and closed the bathrooms at least 10, maybe 20 minutes before reaching a station, so that was quite hard sometimes.

Watching a ton of merchants jump out at each station and then jump back on with their stuff as the train started leaving was quite a sight to see!

It sure was a special experience I'm happy I had!