Kosiak, Mountain summit in Feistritz im Rosental, Austria.

Kosiak is a 2024-metre summit in the Karawanks, about one kilometre north of the main ridge that forms the Austrian-Slovenian border. Its south flank is steep grassy slope, while the west and east flanks are rocky with scree below the cliffs; the treeline lies at roughly 1600 metres. A marked loop, the Friedrich-Zopp-Steig, starts at the Klagenfurter Hütte (1664 m) and reaches the top in about an hour.

The Kosiak lies about one kilometre north of the Karawanks main ridge, which here forms the Austrian-Slovenian border. The Friedrich-Zopp-Steig, a marked circuit from the Klagenfurter Hütte (1664 m), is the normal route to the 2024 m summit; both the south-west and south-east variants take about an hour. In winter the south-west flank is a popular ski tour descent.

The normal route from Klagenfurter Hütte is the marked Friedrich-Zopp-Steig, named after a mountaineer; hikers usually ascend on the west side and descend on the east. The peak also has Slovenian and German names, Kozjak or Ovčji vrh and Geißberg, used on either side of the Karawanks.

The area is best visited during summer and early autumn when conditions are most stable and trails remain clear of snow and ice. Sturdy footwear and weather protection are essential, as conditions can change rapidly at this altitude.

The summit has three names: Kosiak in German, Kozjak in Slovene and Geißberg in German too, while the Slovene Ovčji vrh means "sheep's peak". The Friedrich-Zopp-Steig, the marked route from the Klagenfurter Hütte, is named after a person, and the two variants of this loop each take about an hour.