Asbyrgi

Asbyrgi is a canyon shaped like a horseshoe, roughly three and a half kilometres long and a kilometre across, with walls around a hundred metres high and a free-standing rock island, Eyjan, splitting the middle of it. Sheltered from the wind, the floor carries birch and willow woodland that counts as dense by Icelandic standards, with a small pond, Botnstjorn, at the closed end beneath the cliffs. Geologists attribute the shape to catastrophic glacial floods down the Jokulsa a Fjollum; the older explanation is that it is a hoofprint left by Odin's horse. Marked trails run along the floor, around the pond and up onto the rim.

What you actually see

• The head wall - the sheer curved cliff at the closed end above Botnstjorn pond.
• Eyjan - the rock island in the middle of the canyon, with a path over the top.
• The birch wood - unusually dense woodland on the sheltered canyon floor.
• The rim trails - routes climbing out of the canyon for views down its length.

When to go

May to September for open trails and leaf on the birch, with late September giving autumn colour on the canyon floor. The visitor centre operates in summer and has trail information. The site is quieter than Dettifoss to the south and rarely feels crowded even in July, especially in the late afternoon.

Honest expectations

It is a walking site rather than a viewpoint, and without a couple of hours on foot there is little to see from the car park. The floor is flat and enclosed, so views only open up after a climb. Trails are muddy after rain and midges appear on still summer evenings. Facilities are limited to the campsite area.

Nearby

Dettifoss lies at the southern end of the same canyon system, with Husavik west on the coast.