You see these causeways, these bridges, leading into the island. They had a fairly advanced dam system to collect fresh water from the rain while also to control flooding. In fact, a lot of that was destroyed when the conquistadors came in Mexico City, which eventually gets founded over this lake, is going to have issues with flooding for some time in the future. In fact, the Spanish, in order to control the flooding, end up draining this lake, and this is where Mexico City forms. But the big takeaway here is near the end of the Aztec civilization, as we get to the 100 years before the conquistadors arrive, you have this empire form, this empire which starts as an alliance of city states but eventually becomes a tributary empire. Unlike the neighboring Mayans, which were on the Yucatan Peninsula, on this map they would be in this region right over here, the neighboring Mayans were autonomous city states, some might have had more power, more influence at different times, but the Aztec tributary state means the other city states are paying tribute to Tenochtitlan. They are paying revenue, they are paying service to what essentially is the capital or the seat of that empire until it is conquered by the Spanish.