What are trade routes and how can I get them to bring in more gold?
Cities in your empire automatically have trade routes to other cities, as long as they are connected by some sort of trade network (roads, rivers, ocean, etc.). At the beginning of the game, each city can only have one trade route (although other cities can have trade routes to it), but this number can be increased with various technologies, resources, and UN resolutions. Cities will each use the most profitable trade routes possible, and foreign trade routes (unlocked by open borders with a nation) are generally more profitable than shorter, domestic ones.
