This dramatic desert section of the Great Wall snakes its way up into the desolate Hei Shan (Black Mountains). Originally built in 1539, it was restored in 1988 and is supposedly as far northwest as the Wall goes, but there are actually sites farther west near Dunhuang. Two sections of Wall are here, both of which are worthwhile, although the second one sees less visitors and offers better views over the desert. The Wall here rises at a 45-degree angle for half a kilometer (1,640 ft.) which makes for a sweaty 20-minute climb, but the effort is rewarded with astounding views over the seemingly endless flat desert. You can take a different path back down from the last watchtower. At the top, past visitors have arranged stones into the equivalent of "John loves Mary." This section is 8km (5 miles) north of the fort, and can be reached by taxi or bike. Take plenty of water.