There are four landmasses in the Americas. The Florida panhandle has a rebel settlement, Cuba has a Rebel settlement, and northern Brazil has a rebel settlement. You must approach the Yucatan from the north, just west of Cuba, because you can't disembark anywhere else. Yucatan has three Aztec settlements, in a line, from north to south. Have fun. BTW, Aztecs are in game from get-go. Um, if you "toggle_fow", you can mosey over and take a peek.