The History Channel has a site on the History of Mexico that includes several short videos accessible to English Language Learners.
The clips include ones on the Maya and Aztecs, as well as more modern history.
The site also has a fair amount of text that’s probably accessible to Intermediate English Language Learners.
I’ve placed the link in two places. It’s on my Geography page under Latin America. It’s also on my World History page under The Middle Ages.