China Photo: The Great Wall
Photo: China
Photograph by Gavin Hellier/Getty Images
Sunlight brightens the flanks of China's Great Wall—one of the most ambitious construction projects in human history. The wall was a barrier between China and "barbarian" lands.
• More About China


SPECIAL ADVERTISING SECTION
Photo: Valero train
Interactive Map
Explore solutions to the world's challenges.
Photo: The Cloud Gate in Chicago
Download City Guides
Check out the local hotspots.
National Geographic
Expeditions
Photo: Greek ruins
Travel with some of the most prominent specialists in the world.