Seven kilometers (4 1/3 miles) away from the Fort lies this fairly untouched crumbling bit of the Great Wall and watchtower. The Taolai River that runs through a steep gorge near the tower makes for a dramatic sunset photo op. On the way you'll notice that, true to form, history hasn't stood in the way of "progress" and an expressway runs directly under the wall, while the rail line runs through it! If the glass-floored platform over the gorge at the "visitor center" isn't scary enough you can strap on a body harness and be pitched out over the gorge via a cable (¥31), but remember that in the event of an accident, you're unlikely to sue and win in China. It's also worth visiting the mock-up Chinese military encampment 1km (1/2 mile) back toward the ticket office. There are stone yurts, catapults, cannons, and the opportunity to try your hand at some archery (¥1 per arrow). But best of all is a rickety suspension bridge across the gorge that gives stunning views in both directions. Make sure your taxi waits for you, as it's difficult to arrange a car back to town.