This 9m-tall ruin is the largest of the southern Silk Road Buddhist stupas yet discovered. Built between the 3rd and 5th centuries for a wealthy Khotanese monastery, it might have been visited by the Chinese monk Faxian in AD 401 on his way to India. It was certainly explored by archaeologist Aurel Stein, who excavated the site in 1901, and declared it a magnificent ruin. Stein's original work also uncovered 91 large Buddhist statues (now all sadly gone).
Rawaq is about 50km north of Hotan and it's best to go with a guide who knows the site, as taxi drivers have been known to get lost.