The time it would take to walk the entire Great Wall of China would depend on a number of factors, including the starting point, the route taken, and the pace of walking. A hiker walking at a moderate pace of 5 kilometers (3 miles) per hour would take around 1,500 days to walk the entire Great Wall. This does not include time for rest, sightseeing, or other activities.
It is important to note that walking the entire Great Wall of China is not a safe or practical endeavor. The Wall is often located in remote and rugged areas, and there is a risk of encountering bad weather, wildlife, and other dangers. Additionally, some sections of the Wall are not accessible to the public.