In an age of Google Maps and GPS, it seems strange to think that there was a time when no one had any idea what the Earth really looked like. That began to change in 1570 when cartographer Abraham Ortelius and publisher Gilles Coppens de Diest released the Theatrum Orbis Terrarum (“Theatre of the World”), considered today to be the first true modern atlas. While the mistakes are pretty obvious now, on its publication it represented one of the most influential documents in cartography.