Thórsmörk

thumb|upright|Upper: Ash covered the valley in early June 2010, immediately after the eruption. Lower: The same area, in September 2011 thumb|Near Básar, in Þórsmörk Thórsmörk (, ) is a mountain ridge in Iceland that was named after the Norse god Thor (Þór). It is situated in the south of Iceland between the glaciers Tindfjallajökull and Eyjafjallajökull. The name "Thórsmörk" properly refers only to the mountain ridge between the rivers Krossá, Þröngá, and Markarfljót, but is sometimes used informally to describe a wider area that includes the region between Thórsmörk and Eyjafjallajökull. Thórsmörk is one of the most popular hiking areas in Iceland.

In the valley, the river Krossá winds between the mountains. The valley is closed in between glaciers, Mýrdalsjökull being at the rear end of the valley. This leads to an especially warm climate, better than in the rest of south Iceland. In the protected valley, green vegetation of moss, fern, birchwood, and other small shrubs are found.