Watchtowers: Mutianyu Great Wall is densely populated with watchtowers

Watchtowers: Mutianyu Great Wall is densely populated with watchtowers. In less than 500 meters from Mutianyu No. 1 Watchtower (Dajiaolou) to Mutianyu No. 4 Watchtower (Zhengguan Pass), there are four watchtowers. From No. 1 Watchtower to No. 20 Watchtower, which is only 3000 meters in length, there are a total of 25 watchtowers, enemy platforms, wall platforms, and barracks. This section of the Great Wall, where there is an watchtower approximately every hundred meters, is also uncommon.