Almost all inland Celtic “cities” of western Europe were built around strong fortifiable positions, aka oppida. They were definitely well planned for defense ag

Almost all inland Celtic “cities” of western Europe were built around strong fortifiable positions, aka oppida. They were definitely well planned for defense against tribal warfare and tribal invasions. Aztec cities (probably all cities) had similar root motivations—-control and defend territory. Bibracte near Autun in Burgundy — the city Julius Ceasar had to conquer — is built at the top of a 900 meter hill; Pyrene/Heuneburg built on a rocky spur overlooking the Danube in southern Germany is considered the first real city north of the Alps. Titelberg in Luxembourg was built on a site easily defended on three of four sides and with plenty of space at the top. One interesting exception—-Milan (Mediolanum). Like ancient Mexico City its defenses consisted of water; tributaries to the Po and surrounding marshes. Venice is even more like Tenochtitlan and a more radical and more “modern” version of Milan. The Venetia hit chased into their lagoon thanks to Attila and waves if Goths. You are right that Tenochtitlan had a much more obviously planned lurban structure. But the “organics” of Venice have their own logic, partly partly due to tides and winds but mainly due to a focus on commercial districts rather than religious/ceremonial districts. In 1500 both cities were very large: Tenochtitlan was close to 300,000 and Venice close to 200,000.