The Museo Nacional de Antropología (MNA, or National Museum of Anthropology) is a national museum of Mexico. It is the most visited museum in Mexico. The museum has 23 rooms for exhibits and covers an area of 79,700 square meters (almost 8 hectares) or 857,890 square feet (almost 20 acres). Most known is the Stone of the Sun (or the Aztec calendar stone).
I have added pictures from the "Mexica" section, the other sections coming later. To visit this fantastic museum is highly recommended.