The SPB Metro system, one of the deepest in the world. But also one of the prettiest too. Here's my example to the SPB Metro in TSW2. The trains are the TЧ1 and the TЧ5. The best would be to have all the lines. https://www.google.no/imgres?imgurl...hUKEwjljt3n7NLrAhVGyyoKHYwSB8oQMygqegUIARDvAQ The link is to a picture and a video of the SPB metro. There are also some trains that I didn't mention above. Here's a map of the metro. It's not the newest map, sorry. And if you are considering this route PLZ add the "Warning, the doors are closing" button, and make sure it works! Just ask if you want more info
