Mexico City has now grown to such a size that it roughly covers the same area as the 5 lakes of the Valley of Mexico: Lake Zumpango, Lake Xaltocan, Lake Texcoco, Lake Xochimilco and Lake Chalco. In fact, the shape of the city almost perfectly matches the lakes’ basin. In the image above I drew an approximation of where the shoreline might have been over a satellite image of the city today. Habitation has spread into the mountains to the west and south, but primarily development has remained concentrated in areas where water easily flows. I believe it was the early 1600’s when Lake Texcoco was drained with canals and irrigation ditches. Today a city has grown to take its place completely.
The outline of the island capital of Tenochtitlan can still be seen in the arrangement of the streets and residential blocks in the old colonial section of Mexico City. I was able to easily trace the island’s shoreline just be following the main streets. Interestingly enough, the five major causeways that connected Tenochtitlan to the mainland endure as primary streets radiating away from the Zócalo. And of course the Zócalo square is the very same place where Montezuma’s palace stood.