HUANGGUACHENG
http://www.chinahighlights.com/greatwall/section/huanghuacheng-greatwall.htm
http://www.travelchinaguide.com/china_great_wall/scene/beijing/huanghua.htm
Hi, Kilian, as there’s no direct bus from Huanghuahcheng Great Wall to Beijing, so the best
option is:
1: take a bus No. 936 (branch) at Xishuiyu (Shuichangcheng) station, then get off at
Huairou shichangcun zhan station (21stops along the way).
2: cross the street then take a bus No. 936 or No 867 back to Beijing (Dongzhimen station).
So people may start your Huanghuacheng Great Wall hike either from
Huanghuacheng Reservior or Jintang Lake. To get to Huanghuacheng
Great Wall by bus, you need to take Bus 916 from Dongzhimen
Transportation Hub to Huairou District and get off at the stop of
Nanhuayuan Block 3 （南华园三区), then walk about 100m and change for
the special bus line from Huairou to Huanghuacheng Water Great Wall
（怀柔—水长城 公交专线）.
http://www.saporedicina.com/english/huanghua-great-wall-of-china/