Kötschach-Mauthen is a market town in the district of Hermagor in Carinthia in Austria. The municipality lies 34 km (21 mi) in the west of Hermagor at the transition of the upper Gail Valley into the Lesachtal, between the Gailtal and Carnic Alps. It is located at an important road junction: in the north, the highway leads up to Gailberg Saddle and the market town of Oberdrauburg, in the south to Plöcken Pass on the Carinthian border with the Carnian region of Friuli, Italy.

Late Gothic parish church Our Lady (colloquially Gailtaler Dom, "Gailtal Cathedral") in Kötschach, first mentioned in 1399, rebuilt extensively from 1518 to 1527 according to plans designed by Bartholomäus Viertaler
St Marcus Church in Mauthen, first mentioned in 1466
World War I Museum 1915–18
Ruins of Weidenburg Castle, first mentioned in 1225, later held by the Meinhardiner Counts of Gorizia and their Graben von Stein descendants, acquired by George Khevenhüller in 1571; the Khevenhüller family had a new castle erected beneath the ruins about 1615
Ruined Pittersberg Castle, first mentioned in 1252, held by the Counts of Gorizia
Late Gothic Mandorf Castle, erected by Ortenburg ministeriales first mentioned in 1521