Ásbyrgi is one of the wonders of nature, a wide, horseshoe-shaped canyon with sheer cliff faces up to 100 m high. It is 3.5 km long and over 1 km wide. At its innermost end lies Botnstjörn, a small pond surrounded by luxuriant vegetation. A distinctive rock formation rises up from the centre of Ásbyrgi, up to 250 m wide, known as Eyjan.
The area is covered in woodland consisting mainly of birch, willow and mountain ash. Several thousand recently planted pines also prosper. Arctic fulmar nest on the steep cliffs, while many other birds prefer the woods and meadows.
Ásbyrgi was formed by two or more catastrophic floods caused by glacial bursts from the northern part of the Vatnajökull ice cap, one between eight and ten thousand years ago and a second approximately three thousand years ago. Since then the bed of the river has moved eastwards. However according to legend, Sleipnir, the Norse god Odin's eight-legged horse, put one of his hooves down as the god rode by.
Although Ásbyrgi is part of the National Park, it is run by the Iceland Forest Service.
Ás in Kelduhverfi
For centuries, Ás in Kelduhverfi was one of Iceland's greatest manor farms. Its land was richly endowed with woodland and fertile meadows, and it included a number of smallholdings.
Powerful floods in the River Jökulsá in the 17th and 18th centuries destroyed many of the pastures and transformed Ás from a 'prosperous manor to a large and toilsome peasant hovel'.
A church stood in the estate in earlier centuries, but it had fallen into disuse by 1816. The settlement at Svínadalur was for a long time part of the estate of Ás, and for a long time a mountain dairy (Icelandic: sel) seems to have operated there. It was occupied throughout the 19th century, and right up to 1946. Historical records mention mountain dairies and small cottages in other parts of the Ás estate.
The settlement at Ásbyrgi, one of the old smallholdings of Ás, has been occupied more or less continuously for hundreds of years. The Iceland Forest Service acquired Ásbyrgi in 1928 and enclosed its innermost area.