關城

defensive fort over border post

mountain pass / to close; to shut; to turn off / to confine; to lock (sb) up; to shut (sb in a room, a bird in a cage etc) / to concern; to involve

city walls / city / town / CL:座[zuo4],道[dao4],個|个[ge4]

Jiayuguan fort in the Gansu corridor / Ming dynasty military fort, the western end of the Great Wall