An N1 roadhouse marks the Route 85 Ásbyrgi junction, behind which you’ll find a golf course, the National Parks Visitor Centre and the park’s main campsite. At this end of the park the gorge is very broad and waterless, the river having shifted course long ago leaving a flat grassland between low walls. You can get a good view of this from Eyjar, a long, flat-topped island of rock near the campsite which can be scaled easily enough from its northern end.

Better, though, is Ásbyrgi, where the road dead-ends 5km south at a pond fringed in birch and pine woods, beyond which rises a vertical, 90m-high amphitheatre of dark rock patched in orange lichens, home to a colony of gurgling fulmars. Legend has it that this is the hoofprint of the Norse god Óðinn’s eight-legged steed Sleipnir, though geologists believe that the canyon was carved by a series of titanic jökulhlaups, volcanically induced flash-floods that exploded out from underneath Vatnajökull. Just avoid it in the late afternoon, when the sun catches the cliffs: it looks most romantic, but half of Iceland descends to watch. The view from the top is spectacular, too, though to get up here you need to follow the Dettifoss trail.