I really can’t get on board with canals. That you can do it with city placement seems just random. IRL there are only two canals worth speaking about. They are amazing feats of engineering, but I don’t see how Civ could ever represent that. Making canals districts or improvements would make them too common, and making a canal a wonder would make it too hard. And any canal in Civ is just not going to have the importance of Suez or Panama canals. Sorry, but I just don’t get it. If Civ is going to have these sort of “mega structures”, it needs a bigger rethink. What about the Channel Tunnel? Hydro Electric Schemes, like the Three Gorges? Mountain passes. etc. These might or might not sound “cool”, but unless there is a more in-depth trade, travel or power system in the game, it’s just sort of window dressing. To me, this stuff makes more sense in a game like EU4, where you have a more complex trade system complete with “trade nodes”. If Civ VI had a more complex trade system late game, then canals and railways and underground rail and all those things might grow out of that organically.