John Hessler considers answers to some of the key questions raised by the map's representation of the New World, including "How was it possible for a small group of cartographers to have produced a view of the world so radical for its time and so close to the one we recognize today?"; and "What evidence did they possess to show the existence of the Pacific Ocean when neither Vasco Nûnez de Balboa nor Ferdinand Magellan had yet reached it?". There are no easy answers, and yet, as this fascinating book reveals, this group of unknowns created some of the most important maps in the history of cartography, and afford us a glimpse into an age when accepted scientific and geographic principles fell away, spawning the birth of modernity.