Krn (pronounced [ˈkəɾn]; 2,244 metres or 7,362 feet) is a mountain of the southwestern Julian Alps in northwestern Slovenia. It is the highest mountain of the Krn Mountains. The mountain is located about 50 kilometres (31 mi) from the Adriatic Sea. The Soča River flows west of the peak, and the smaller Lepenjica River northeast and the Tolminka River southwest of it. Krn has a mighty western wall, which can be best seen from Kobarid or Drežnica.
On the southern slope of the mountain lie the small villages of Vrsno, Krn, Drežnica, Drežniške Ravne, and Magozd. On the northern side lies Lake Krn, the largest glacial lake in Slovenia.
During the First World War, the Battles of the Isonzo took place in the area. The 3rd Regiment of Alpini had taken Mount Krn's peak on 16 June 1915 in a daring raid where the elite Italian unit climbed the peak's cliffs "with their boots swaddled in sacks of straw to reduce noise," some of them barefoot, and others wearing only socks, and battled the Hungarian battalion of the 4th Honved Regiment. "It was a glorious success, the first of the war, presaging others that never materialized."The top of neighbouring Mount Batognica (2,164 m or 7,100 ft) was blown off by an accidental weapon depot explosion. Many remnants from the war remain scattered around the peak.