The First Pier of the Great Wall (天下第一墩) is a large earthen beacon tower standing on the north rim of the Taolai River gorge, about 7 kilometres south of the Jiayu Pass fortress. It marks the southern terminus of the Ming Dynasty Great Wall's western section — the point where the wall's builders decided the gorge was an adequate natural barrier and the constructed wall could stop. The tower itself is a rammed-earth beacon platform about 14 metres tall, original Ming construction, with the remaining stump of the connecting wall running north from it.
The gorge view is the more impressive element: the Taolai River has cut a canyon 70 metres deep through the desert plateau, and the contrast between the flat Gobi above and the sudden vertical drop is dramatic. A suspension bridge across the gorge allows you to view the tower from the opposite side. A small museum at the site tells the story of the wall's construction in this area with original tools and photographs of the excavation work. The site is usually quieter than the main Jiayu Pass complex and is worth the short detour.