Kerið is a volcanic crater lake located in the Grímsnes area along the Golden Circle. It is one of several crater lakes in the area. The caldera, like the other volcanic rock in the area, is composed of a red (rather than black) volcanic rock. The caldera itself is approximately 55 m deep, 170 m wide, and 270 m across. Kerið’s caldera is one of the three most recognizable volcanic craters because at approximately 3,000 years old, it is only half the age of most of the surrounding volcanic features.
While most of the crater is steep-walled with little vegetation, one wall is sloped more gently and blanketed with a deep moss, and can be descended fairly easily. The lake itself is fairly shallow), but due to minerals from the soil, is an opaque and strikingly vivid aquamarine.
It is not part of most scheduled golden circle tours since the owners charge a small fee to visit it. It is however possible to add the visit during a private tour paying the entrance fee on the spot.