The Great Wall of China, one of the world’s most iconic man-made structures, has long fascinated people with its grand scale. But just how long is it? The answer is more complex than you might think—because it’s not a single continuous wall, but a network of walls built across different dynasties.

In 2012, China’s State Administration of Cultural Heritage released an official measurement after a five-year survey: the total length of the Great Wall, including all sections built from the Spring and Autumn Period (770–476 BC) to the Ming Dynasty (1368–1644), is 21,196.18 kilometers. This number covers not just the well-known stone and brick walls, but also earthen ramparts, beacon towers, and passes spread across 15 provinces, municipalities, and autonomous regions.

To understand this length, consider a comparison: if you stretched the Great Wall end to end, it could circle the Earth’s equator roughly halfway. But different dynasties contributed to different parts of this total. The Qin Dynasty (221–206 BC), which first unified China, built about 5,000 kilometers of wall to defend against northern nomads. The Han Dynasty (202 BC–220 AD) expanded it to over 10,000 kilometers, extending westward to protect the Silk Road. The Ming Dynasty, the last to majorly rebuild the wall, constructed around 8,850 kilometers—much of the well-preserved sections visitors see today, like Badaling and Mutianyu, are Ming-era.

Not all sections are intact, though. Over time, some parts have eroded due to weather, while others were damaged by human activity. Still, the official length reflects the full scope of this ancient defensive project.

Beyond numbers, the Great Wall’s length symbolizes the effort and ingenuity of ancient Chinese people. It winds through mountains, deserts, and plains, adapting to diverse landscapes. For visitors, knowing its total length helps appreciate not just its physical size, but also its role as a cultural symbol of China’s history and unity.

In short, the Great Wall’s 21,196.18-kilometer length is a testament to its status as one of humanity’s greatest architectural achievements—connecting centuries of history in every meter.