Háifoss

The drop is the point. The Fossá falls 122 m into a canyon here, and only three waterfalls in Iceland are higher. A second waterfall, Granni, comes down beside it, so both are in view from the same spot.

The rim is bare ground. There are no guard rails and no viewing platforms, and in good weather the falls throw large rainbows across the gorge. The walk down into the canyon changes the view completely: from the bottom you see the fall at full height against the walls, and the wind is weaker there than at the top. The rock formations along the canyon are worth the descent on their own.

• Access road: 4x4 only, and potholed. Go slowly.
• Navigation: Google Maps can route you onto the rougher track. The approach on road 332, past Gljásteinn Hostel, is bumpy but manageable.
• No barriers: there are no guard rails and no viewing platforms at the rim.
• Wind: gusts at the top viewpoint can knock you off your feet. Lower in the canyon they ease off.
• Rainbows: in good weather large rainbows form over the falls.

Nearly everyone drives. The access road is 4x4 only and potholed, so allow extra time for the last stretch. The car park sits above the waterfall, and a trail leads from the top of the falls down to the bottom — demanding in places, but nothing extreme. The other way in is on foot from the reconstructed farm Þjóðveldisbærinn Stöng, following the Fossá: five to six hours there and back.

Better: a clear, calm day. In good weather the falls throw large rainbows, and the canyon walls and rock formations show clearly.

Avoid: windy days. The rim is unfenced, and gusts on the top viewpoint have been strong enough to put visitors on their knees.

Wind eases as you descend into the canyon, so the view from the bottom can still work on a rough day, even when the top is unusable.