Very cool project, I misread that as "megalopolis" but I take it that a megapolis is a city with thousands of residents - 50K in the case of Calakmul[1], which is large for a premodern city, but only 1/4 the size of Tenochtitlan[2].

1: https://en.wikipedia.org/wiki/Calakmul#Population_and_extent

2: https://en.wikipedia.org/wiki/Tenochtitlan#History