In my current game, I found something awkward: I have founded a city adjacent to another civ's city. Suddenly, I noticed that both cities were connected by a railway. It's not easy to tell in the map view but it's clear when pressing 'T' for showing the transport network. The strange thing was that I had not discovered Railroad neither did the other civ. In fact, the game was pretty much in its begginings. I don't remember seeing this before, although I avoid building cities adjacent to other cities, either mine or not. Have anyone experienced this phenomenon of instant urban railways? Just for the record, I play version 474.03.