East of Reykjavik lies a mountain named Hengill. Hengill was formed from a Palagomite tuff and its highest point is around 800 metres above sea level. Hengill is a central volcano and has a giant magma chamber beneath it.
Marble Caves of Patagonia in Chile – Lake Carrera. The lake is on the border of Argentina and Chile, and the caves are located on the side of Chile. The caves are the three main grotto: Chapel (La capillaries), Church (El Catedral) and Cave (Cueva).