Not the sandwich shop. Underground commuter rail. Many of the great cities of the world have subway systems, metro systems, underground systems, what have you—they're trains underground is what counts. They tend to be part of the lifeblood of the city, an element of its character, a point of pride (or occasionally shame) for its citizens, and a record of its history. They develop their own unique cultures and quirks. In short, they are kind of awesome...which is why we made this index.
Subway systems of the world