The Great Wall of China

Introduction

Of all the engineering achievements in the long and astonishing history of human civilization, few rival the Great Wall of China in sheer audacity, scale, and endurance. Known in Chinese as Wanli Changcheng, meaning the Ten-Thousand-Li Long Wall, it is the most extensive fortification system ever constructed by human hands. Stretching across mountains, deserts, river valleys, and plains, the wall snakes along the natural spine of northern China for thousands of kilometers, climbing impossible ridgelines, disappearing into eroded badlands, and emerging again as a massive ribbon of stone, brick, and tamped earth against the open sky. It is at once a monument to the power of centralized imperial authority, a record of the suffering of hundreds of thousands of forced laborers, a symbol of a civilization's determination to define and protect its borders, and one of the most visited and most recognized structures anywhere on earth.

The wall that most visitors think of when they picture the Great Wall is not a single wall built at a single moment in time. It is the product of more than two thousand years of construction, expansion, repair, and rebuilding spanning more than a dozen dynasties. The total length of all wall sections ever built, according to the most comprehensive archaeological survey conducted by China's State Administration of Cultural Heritage in 2012, is approximately 21,196 kilometers, about 13,171 miles. However, much of this total includes natural barriers such as rivers, ridgelines, and mountain escarpments incorporated as part of the defensive system, as well as earthen ramparts and ditches that are no longer easily visible. The iconic section that tourists climb at locations like Badaling and Mutianyu near Beijing, with its tall crenellated brick towers and broad paved walkway, was built primarily during the Ming Dynasty from 1368 to 1644 and stretches approximately 8,850 kilometers, about 5,500 miles, from Shanhaiguan on the Bohai Sea coast in the east to Jiayuguan Fort at the edge of the Gobi Desert in the west.

No single monument in the world concentrates so many stories within its stones. There are the stories of the generals who commanded its construction and the emperors who ordered it. There are the stories of the hundreds of thousands of soldiers, peasants, and convicts who built it, many of whom died in the process. There are stories of the nomadic peoples against whom the wall was raised and of the occasions when those peoples breached, bypassed, or simply walked through the wall's gates, rendering it militarily irrelevant. There are stories of the silk merchants and diplomatic envoys who passed through its gates and guardhouses along the routes of the Silk Road. And there are the more recent stories of the wall's rediscovery by the outside world, its designation as a UNESCO World Heritage Site in 1987, its selection as one of the New Seven Wonders of the World in a global poll in 2007, and the ongoing battle to preserve what remains of it against the forces of tourism, development, and climate change.

This article tells all of those stories in depth, tracing the wall from its earliest origins in the political violence of the Warring States period through the remarkable engineering achievement of the Ming Dynasty to the complex challenges of the present day.

The Myth of Visibility from Space

Before tracing the history of the wall, it is worth addressing one of the most persistent and most thoroughly debunked myths associated with it: the claim that the Great Wall of China is visible from space, or, in the most extreme versions of the legend, from the Moon itself. This myth has been repeated so frequently in textbooks, travel brochures, documentaries, and casual conversation that it has achieved the status of received wisdom. It is, however, definitively and demonstrably false.