The Grinding Ice.

Existed in the Valian Years and Valian Years of the Trees, First age and Second age. Was moved outside the world in the end of the Second age due to the downfall of Númenor.

Outermost north of Aman and Oiomurë and between the Central Highlands of Endor; the Mortal Lands; Middle-earth, the shores of Belegaer drew near to eachother. In this narrow strait through which the cold waters of the Encircling Sea and Belegaer flowed together the ice-cap of the north melted with vast fogs and deadly cold mists. The streams was filled with clashing and grinding hills of ice.