The subway, the underground, the metro, the tube — whatever you want to call it, this form of public transport has been taking city dwellers from A to B for nearly hundreds of years. As anyone who uses it regularly will tell you, the system is far from perfect. It's horribly busy at peak times, and some lines are less reliable than others. In many places, such as New York, the infrastructure is so dated that travelers are faced with conditions they wouldn't even dream of if they could just drive everywhere.
Nonetheless, millions of people rely on this as their primary form of transport. Living in an urban area, the subway is one of the few things that brings those from all walks of life together. It also means that it's home to some pretty strange sights at times, but that's all part of the experience. If you take a subway ride without witnessing something unexpected, did you really go on the subway at all?