The mayan civilization was in Northern Central America. Like Guatemala, Honduras, and Belize. So Southern Mexico but Northern Central America.
Unlike the Aztec and the Inca, the mayan didn't really have a central capital city. The Roman Empire had Rome, the greeks had Athens, and so on. The maya didn't have one huge central hub. Instead, the maya had city states. We don't know how many city states there were. We keep discovering new ones like every other year in the jungles of Southern Mexico and Central America.