Huilo-Huilo (Spanish pronunciation: [ˈwilo ˈwilo]  audio , Pronounced: /ˈwiːloʊ ˈwiːloʊ/ WEEL-oh-WEEL-oh) is a waterfall located in Huilo-Huilo Biological Reserve in southern Chile. It lies next to Neltume in the international road to Hua Hum Pass, in the border to Argentina. The waters of the Huilo-Huilo Falls originates in Lácar Lake in Argentina. During the summer it frequently dries, as consequence of low precipitation and subterranean runoff. As consequence of this infiltration a large aquifer is situated under Mocho-Choshuenco volcano.