Hochosterwitz Castle (German: Burg Hochosterwitz, Slovene: Grad Ostrovica) is a castle in Austria, considered one of Austria's most impressive medieval castles. It is on a 172-metre-high (564 ft) dolomite rock near Sankt Georgen am Längsee, east of the town of Sankt Veit an der Glan in Carinthia. The rock castle is one of the state's landmarks and a major tourist attraction.