Aztalan is a town in Jefferson County, Wisconsin, United States. The population was 1,457 at the 2010 census. The unincorporated communities of Aztalan and Jefferson Junction are located in the town. According to the United States Census Bureau, the town has a total area of 24.6 square miles, of which 24.1 square miles is land and 0.54 squ…Aztalan is a town in Jefferson County, Wisconsin, United States. The population was 1,457 at the 2010 census. The unincorporated communities of Aztalan and Jefferson Junction are located in the town. According to the United States Census Bureau, the town has a total area of 24.6 square miles, of which 24.1 square miles is land and 0.54 square miles, or 2.17%, is water.