Flókadalur, a broad, grassy valley, actually two, down which flow the rivers Flókadalsá and Geirsá. In Flókadalsá, which comes from the Ok mountain, there are salmon and trout. Ok (1,198 m) is made of basalt and was formed by an eruption late in the Ice Age. It has a small glacier on top that has got much smaller recently, leaving the crater bare.