Kerið is a volcanic crater with a lake in the bottom, and it is one of those places that looks as though someone staged it. The walls are a deep rusty red, made of scoria, the porous volcanic rock that forms when lava cools quickly, with patches of moss and grass clinging to the slopes. In the middle is a pool of intensely blue-green water, which shows up especially well against the red on a bright day. The crater is about two hundred and seventy metres across and the lake is shallow in places but deep in others.
It sits along the Grímsnes area in south Iceland, a short ride from Selfoss, and it is one of the easiest stops of the Golden Circle. There is a small car park, and an entry fee is usually charged because the land is privately owned. A path runs around the rim and another leads down to the water's edge, and you can walk around the whole circuit in a short time. In summer, birds nest in the crater and the air carries the smell of wet moss and cold stone, while in winter the lake freezes and the red slopes are dusted with snow.
The riding on this section is gentle. The roads are paved, the bends are broad, and the landscape of farms, greenhouses and low hills is soft compared with the more dramatic parts of the country. This region is warmed by geothermal heat and many of the greenhouses grow tomatoes and cucumbers in the middle of an Icelandic winter. Keep an eye on speed, as police patrols are common near tourist sites, and watch for sheep and slow-moving farm vehicles.
Wind is a factor at any time of year and it can be strong on the exposed rim, so hold on to your hat and keep your gloves on. A rain jacket is a good idea even on a bright morning.
Fuel and food are straightforward. Selfoss, thirteen kilometres away, is a proper town with pumps, a big supermarket and plenty of cafes, and Hveragerði, a little further, is the greenhouse town known for its hot-spring baths and bakeries. If you are doing the whole Golden Circle in a day, filling in Selfoss before or after Kerið is the natural rhythm.
The crater was long thought to be the result of a collapsed volcanic cone, a magma chamber that emptied and fell in on itself. Whatever the exact history, it makes for a very satisfying ten-minute stop on a longer day of riding.