Keri is a staggering circular shaped volcanic crater that is 270 meters long, 170 meter wide, and 55 meters deep with a pond at the bottom that is 7ľ10 meters deep. It is located along the route of the famous Golden Circle (road 35) and located right next to the road, about 10 minutes drive from Selfoss, the largest town in south Iceland. Keri is an awesome monument to the volcanic activity in Iceland and a site not to be missed. After the explosion occurred, about 3000 years ago and once the magma was depleted, the cone collapsed into the magma chamber below, due to the weight of the materials that formed Keri. The caldera, like the other volcanoes in the area, is composed of mostly red (rather than black) volcanic rock due to iron found in the rock. This red rock is plentiful in the area and utilized by owners of cottages in the area for their driveways. Keri is one of the most popular destinations for tourists in the country and an admission fee required at the entrance.
There are several other volcanic craters in the area close to Keri, for example Seyishˇlar and Kerhˇll, collectively called Tjarnarhˇlar. Some of the most popular tourist attractions in south west Iceland are only about 30 to 40 minutes drive from Keri, including the waterfall Faxi, the Geysir area and the majestic waterfall Gullfoss. Occasionally, concerts have been held on small boats or rafts while the audience sits on the inner slopes of the crater.