Cities are almost always built next to water, even today. Before long roads existed connecting distant places, waterways were also the only way to transport thi

Cities are almost always built next to water, even today. Before long roads existed connecting distant places, waterways were also the only way to transport things faraway. It was much, much easier to load a boat with stuff and paddle it or use wind to move it, than it was to try to build much more complex horse-pulled vehicle that could move long distances in the absence of roads (imagine a charrot moved around on plant-covered terrain or even worse, sand).