Sometimes referred to as "Western Badaling" for its resemblance to a section of the Great Wall near Beijing, this part of the Great Wall, about 9 kilometers out from Jiayuguan Fort, was originally built in 1539, through some reconstruction and refurbishment, including the addition of stairs, occurred in 1987. 

Hiking up to the top, which can be very demanding due to the 45 degree inclination you're pitted against on the way up, is worthwhile. You'll be rewarded with sweeping views encompassing the Jiayuguan oasis, forlorn expanses of desert and the glittering peaks of the Qilian mountains. 

If visiting, do make sure that you are indeed at Xuanbi Changcheng (Overhanging Great Wall) and not the smaller section of the wall beside it. That section costs RMB 41 for an experience that just isn't as grand as the one you'll get here.