Keilir was created during subglacial eruptions during last ice age. It´s shape makes it distinctive and according to geologists, it probably is a crater plug. In spite of its steep slopes, it is not too difficult to climb, and the view from its top on a fine day is to be remembered. Keilir is the most distinctive landmark of Reykjanes. On top of the mountain is a concrete table with a view direction map on a metal plate.