North of the Plaza de Armas you'll find the Museo Regional Cuauhnáhuac, whose name is derived from the Aztec word for the surrounding valley, though it's also known as the Palacio de Cortés. The fortresslike building was constructed as a stronghold for Hernán Cortés in 1522, as the region had not been completely conquered at that time. His palace sits atop the ruins of Aztec buildings, some of which have been partially excavated. There are plenty of stone carvings
from the area on display, but the best way to digest all this history is by gazing at the murals Diego Rivera painted between 1927 and 1930 on the top floor.