When Spanish conquistadors marched into the island city of Mexico-Tenochtitlan in 1518, they were stunned by what they encountered. The scale, richness, complexity, and advancement of this capital built by the local Aztecs surpassed anything in Spain at the time. I find this 3D virtual reconstructed Portrait of Tenochtitlan on lake Texcoco to reward endless scrutiny. The sliding overlay of modern Mexico City is genius. I am as much stunned by its grandeur as the first invaders. – KK