Hafrahvammagljufur (Dimmugljufur (Dark canyon))
Hafrahvammagljufur Is (the most spectacular canyon in Iceland. about 15 kilometres long and almost 200 metres deep. In many places near Ytri-Karahnjukur, It is just under 100 metres wide. The canyon was created when Jökulsa a Dal cut its way through the moberg (tuff) ridge Karahnjukar and many other types of rock from successive eras of geological history, which can be clearly seen in the exposed cliffs. Hafrahvammagljufur submerged since the Karahnjukar dam is built.
Iceland - Island Iceland - Island Iceland - Gufudalur
Iceland - Island Iceland - Island Iceland - Island

The canyon was named long ago after the so-called Hafrahvammar, but in recent years, the southem area has acquired the name Dimmugljüfur (Dark canyon). Hafrahvammar consists of grassy hollows on the west side of the canyon area near Ytri Karahnjukur. Nearly 500 metres above sea level there are many interesting moberg (tuff) cliffs and shelves here, and a great variety of Vegetation. There is a large cave in the Innermost section of the hollows called Magnahellir. Shepherds used to take shelter there, and it is named after one of them, Magni from the farm Bru. A folk tale recorded by Sigfus Sigfusson relates that Magni once left a piece of meat there, from his own provisions, for the troll wife's children. Opening into the canyon is the ravine Skessugja, or the troll wife’s gap. It is about 150 metres long, and it can be reached from the north side by a reasonably easy trail. a

Source: public board on site