Burg, Historic museum building in central Klagenfurt, Austria.

The Burg in Klagenfurt is a three-story rectangular block bounded by Burggasse, Paradeisergasse, Bahnhofstraße and Domgasse. Its long pilastered facades have windows crowned with triangles and segmental arches; the Burggasse front has 17 window axes, the south side 10. Inside, an arcaded courtyard is flanked by two- and three-story arcades, with a staircase tower built in 1854 interrupting the south side.

Construction began in 1586 under the Protestant Landstände, following plans by Johann Anton Verda, for the Collegium sapientiae et pietatis, a noble school with its own observatory and a garden labyrinth. From 1604 to 1747 the building housed the Burggraf. The chapel was added in 1733/34, a third storey with pilasters and stuccoed window crowns followed in 1773/74, and the staircase tower in the arcade courtyard dates from 1854.

The Museum Moderner Kunst Kärnten uses the building today, connecting it to the region's art heritage. The name refers to its past role as the burgraves' seat, which remains visible in the architecture and furnishings.

The building is centrally located in Klagenfurt at the intersection of Burggasse and Paradeisergasse streets, easily reached on foot. It is accessible on weekdays and hosts regular exhibitions of contemporary art across multiple gallery spaces.

The chapel's altarpiece fresco by Josef Ferdinand Fromiller shows Saint Domitian hovering over Millstatt Abbey, with a Latin inscription naming him "Archduke and Apostle of Carinthia". The painting records that the abbey's two west towers were once joined by a wooden bridge, as at Gurk Cathedral. Below the wooden oratory box, Fromiller painted the names of the 19 burgraves.