Holsfjoll, or Fjallasveit, is the name of the area to the east of River Jokulsa a Fjollum to the north of the present road # 1. It extends east to the mountain ranges Dimmifjallgardur and Haugsoraefi (1000 m). The first farm was built there in the 14th century (Holl) and later the southernmost one, which is the only inhabited one nowadays, Grimsstadir. In the middle of the 19th century quite a few new farms were built in the area, and in 1859 approximately 100 people lived in the community.
The families, who lived there had to their necessities over a 100 km long bridle path to the trading post at Vopnafiordur (45 km between the closest farms). The quality of the smoked lamb from this area was highly appreciated, but because of overgrazing and the consequent erosion the farming came to an end.
During the last few decades much has been done successfully to reclaim the area and stop the erosion. During summer the road through this area is much frequented by those who want to see Europe’s mightiest waterfall, Dettifoss. It is also accessible from the western side of the river.