Who built the Great Wall of China, and is it related to Dhul-Qarnayn mentioned in Surat Al-Kahf?

The Han Dynasty built the Great Wall of China to protect the country from Bedouin attacks. These two walls are unrelated. The Great Wall of China is built of stones, wood, and clay, while the wall of Dhul-Qarnayn is built of iron and other metals, preventing Gog and Magog from emerging, unlike the Great Wall of China, which can be breached.