Last week, before the rains and the generally crappy weather, I took a trip to Guyaju in Yanqing County, about two hours from Beijing’s center. There are a number of ancient cliff dwellings to hike in and around. No one actually has a clue how they came to be, but it must have taken a ton of time and effort to carve out each cave.
Notably, this was the emptiest “attraction” I’ve been to in China. Very few other people – it was great!