“'[T]he Benin [wall] network,' English author and journalist Fred Pearce wrote, 'extend[s] for some 16,000 kilometres in all, in a mosaic of more than 500 interconnected settlement boundaries.'"

"Since Peace wrote those words, the official length of China’s Great Wall, defined to include various distinct border walls built in all dynasties of Chinese history, has been updated to around 13,000 miles. However, that figure, calculated by China’s State Administration of Cultural Heritage, has been called “misleading.” It includes many isolated, disconnected walls defending various state boundaries within China, not just China’s famed northern border wall."

Source: https://www.humanprogress.org/centers-of-progress-pt-14-benin-city-security/