A part of the Diego Rivera mural of Tenochtitlán, in the Palacio Nacional, Mexico City, 1945. One of Cortés' soldiers, Bernal Díaz del Castillo, dictated a lengthy description of the magnificence of Tenochtitlán in 1519. He was right to be impressed. Cortés and his men entered a city with a population of over 100,000, larger than nearly every European city of the day; Seville, the city from which the conquistadores had embarked, had a mere 40,000 people. Tenochtitlán was a clean city, with brightly painted buildings, bustling commerce, and even a zoo.