Yamagata cast iron is produced in the city of Yamagata, Yamagata Prefecture. Although Yamagata cast iron is thought to date back to the late Heian period (794-1185), it was not until the Edo period (1603-1868) that the cast iron industry began to fully develop. After the end of the Edo period, metal casting grew into a modern craft industry, producing tea ceremony kettles (chagama) and a variety of other products. This region has the largest market share of chagama in Japan as they are highly acclaimed for both their design and quality. A range of techniques such as sand molding, pattern pressing on a sand mold, and surface beating are used to create fine textures. In 1974, Yamagata cast iron was designated as a Japanese traditional craft.