Dragon Kiln Southern Song Imperial Kiln Museum, Hangzhou This the furnace where the main firing was accomplished. Kilns of this type are also called climbing, or snake, kilns. In Japan they are called anagama (cave) kilns. The unfired pots were stacked in saggers (next page) before firing. The kiln is about 40m (131 ft) long by 2m (6.56 ft) wide. It was originally covered, like all kilns, to retain the heat. Working kilns of similar type can be visited today, for example, on Okinawa.