[1] It is one of several crater lakes in the area, known as Iceland's Western Volcanic Zone, which includes the Reykjanes peninsula and the Langjökull Glacier, created as the land moved over a localized hotspot, but it is the one that has the most visually recognizable caldera still intact.

Kerið is the northernmost of four craters situated along an 800-meter fissure called the Tjarnarhólar [ˈtʰja(r)tnarˌhouːlar̥] row.

[4] While most of the crater is steep-walled with little vegetation, one wall is sloped more gently and blanketed with a deep moss.

The lake at the bottom of the crater is fairly shallow (6–14 meters, depending on the level of groundwater); due to minerals from the soil, the water appears aquamarine.

[6] The land on which the crater sits is owned by a private company, Arctic Adventures, which bought the site in 2023.