Pinggu
平谷区
In the hills north of the Eastern Qing Tombs lays this pleasantly large lake. You'll find some unrestored Great Wall here tumbling down to a well-restored fortress perched above the deep water. Since it's a reservoir, there's little development allowed, making it perfect for amateur trailblazing and leisurely water fun. Stay at the Tairen Guesthouse (RMB260 for double).
Tairen Guesthouse, (315)-694-1821, 139-3337-3552. Get there: Long distance bus from Sihui Zhan to Shimen (¥44), then three-wheeler to Shangguanhu (¥30). Return via Zunhua express bus