1) Korean invention 
Hanjeungmak (한증막; 汗蒸幕) is Korean traditional sauna. Intensely hot and dry, it uses traditionally burning wood of pine to heat a domelike kiln made of stone. == History == The first mention of hanjeungmak, initially referred to as Hanjeungso(한증소; 汗蒸所), is found in the Annals of Sejong in the 15th century. The record also sta...