The lake's proximity to the Karlıova Triple Junction has resulted in fluids from the Earth's mantle accumulating in the strata beneath Lake Van, driving some of its geological evolution. Dominating the lake's northern shore is the stratovolcano Mount Süphan. The broad crater of a second, dormant volcano, Mount Nemrut, lies close to the western tip of the lake. There is hydrothermal activity throughout the region.