On the waterfront in Shoningahama park, close to Beppu Daigaku station, this sand bath, one of the most popular of Beppu, is heated by water seeping out of the earth. After donning a traditional yukata and laying down in the hot sand, smiling grandmothers called sunakake-san (sand 'powderers') bury you alive by covering you up to the neck with shovelfuls of burning sand. The name of the game is then to sweat for as long as possible as you gaze at the ocean.