Ásbyrgi is a canyon shaped like a horseshoe, about a kilometre wide and three and a half long, with cliffs rising up to a hundred metres and a forest of birch and willow growing on its floor. It feels like a hidden world, sheltered from the wind, green and quiet, and after the open, rugged landscape around it the effect is almost startling. A rocky island stands in the middle, dividing the canyon's head.
The old story says that the canyon is the hoofprint of Sleipnir, the eight-legged horse of Odin, who touched down here on his flight across the sky. The scientific story is more dramatic: geologists believe that enormous floods of glacial meltwater, released from beneath the ice cap in catastrophic bursts thousands of years ago, tore the canyon from the rock, and the Jökulsá river, which once flowed here, later shifted its course to the east. Either story is worth thinking about as you stand at the head of the canyon.
The road in from the main route is easy and the surface good. The canyon is part of the great national park along the Jökulsá river, which also includes Dettifoss, and the landscape here is a mixture of lava, sand and scrub. Wind can be fierce on the open plain, but inside the canyon it is calm. Traffic is generally light, and the approach has long views of the Arctic horizon.
Nature is the great attraction. The birch forest is one of the few in the north, and in summer it is full of birdsong, with redwings and wrens, and sometimes even ravens and falcons nesting on the cliffs. There are walking paths, a pond at the head of the canyon, and a campsite with a visitor centre near the entrance.
Services near the canyon are limited to the visitor centre and campsite, with a shop and a cafe, but Húsavík is the nearest town of any size. Allow an hour or two for a walk, and go in the morning if you can.