[akiselev]

It's not a coincidence. The conquistadors spent months in Tenochtitlan as guests of Montezuma and wrote extensively about how amazing the urban planning was. They would have preferred to keep the city in tact all things considered.

Since the Aztecs had done all of the hard work of figuring how to build out drainage and stability with the chinampas, the Spaniards built their new buildings on top of the foundations remaining from the Aztec buildings. It then took several centuries to fill in all of the canals and turn them into streets so the layout of Mexico City very much reflects Tenochtitlan.

For example the Zócalo square is right where the Aztec ceremonial center used to be and I believe the Metropolitan Cathedral was originally built on top of the foundations of a minor temple that was built as part of the Templo Mayor complex.