Núpsvötn, a wide and many–streamed glacial river on the western side of Skeiðarársandur, joined by the river Súla some distance upstream. This river often rises considerably, causing big floods when the lake Grænalón by the edge of Skeiðarárjökull forces its way out under the glacier. The whole valley between Lómagnúpur and Skeiðarársandur is very interesting for the tourist but difficult to reach because of the rivers. The rivers Núpsá and Hvítá join in two falls into a beautiful canyon and from then on they are called Núpsvötn. It is possible to make one’s way along the eastern side of the canyon with the help of an iron chain which has been bolted to the rock. A fine day’s hike from the valley across Eystrafjall to Núpsstaðarskógar and Eggjar to Grænalón or to the impressive Súlutindar by the western edge of Skeiðarárjökull.