What is "hammeren"

Hammeren (also Hammerknuden; meaning, "hammerhead-shaped crag of granite") is a protected area and promontory in Denmark on the northernmost point of Bornholm island. It projects into Sæne Bugt bay in the Baltic Sea. The area includes Hammersø, the largest lake on the island and the only tarn in Denmark, and a hill, in height, named Stejlebjerg (or Stieleberg). It is steep to the southwest but slopes gradually to the northeast, and is separated from the rest of the land by a valley.