Open this dynamic book and discover how the greatest explorers in history — from Marco Polo to Neil Armstrong — plunged into the unknown and boldly pieced together the picture of the world we have today. With the help of masterful cross sections, dramatic storytelling, and sidebars that highlight key concepts, places, and technology, immerse yourself in such expeditions as: —Leif Eriksson’s voyage to North America (eleventh century) —Zheng’s...