Went up to Miyun the other week thoroughly enjoyed it. The town itself nothing to do. But the lake area is great plenty of walking trails and some of the great wall is untouched/not touristy. Went on one walk it was a 5hour trek up the mountain with some great views.

No Idea......I do not even know where is that county 

I spent a few months there last year, I got around a bit, but the most fun I had was by taking bus 980 until you come to the last stop.

Miyun has a Wumei, and several KFC branches, as earlier stated a few lakes, and you can go walking. Also, I never made the trip, the great wall there, Gubei - S--- starts with S, but that's 60km from when you actually enter Miyun, but I regret not going, as stated, there are still original pieces there, and they are lesser known spots. 

Also I found many of the restaurants there very reasonably priced, and pretty good eating. 

I never had a problem about it, but foreigners are few and far apart there, so if you go around in the township a bit, you will find people stop and stare