Sangkhalok ware lidded jar, with a celadon glaze. Some of the finest ceramics to have come out of Southeast Asia were produced in Thailand between the late 13th and 15th centuries, at the height of the Sukhothai period. The most famous site was an area of kilns a few kilometres north of Si Satchanalai, the twin city of Sukhothai. Excavation in the early 1980s revealed just how extensive the production was: this was virtually an industrial complex, with two centres close to each other, at Ban Pa Yang and at Ban Koh Noi. At the latter alone there were over 150 kilns in a little over a square kilometres.