Buried beneath modern Mexico City lie the remnants of a nearly 700-year old city that the Spanish conqueror Hernan Cortes described as the most beautiful in the world. During the time of the Aztecs, Tenochtitlan was located in the middle of a shining blue lake and was home to more than 200,000 people. Tenochtitlan was bigger, cleaner, and more elegantly laid out than any European city of its time. The Spanish, fearful of a religion that included human...