"Templo Mayor (translation: main temple) was the centerpiece of Tenochtitlán, the ancient Aztec capital, constructed in 1325 in the marshes of Lake Texcoco. The temple was mowed over and replaced by a cathedral during the Spanish conquest in 1521. Today, the hulking stone ruins lie at the heart of Centro Histórico, embedded in the blueprint of downtown. Surrounded by streets and buildings, it is hard to imagine the temples in their original Aztecan glory, but the nicely organized museum helps paint the full picture." - Scarlett Lindeman