Burg Wildberg, Medieval castle ruin in Kirchschlag bei Linz, Austria

Burg Wildberg is a castle complex stretched from south to north on a ridge above the Haselgraben valley in Kirchschlag bei Linz. The southern hilltop holds the medieval upper castle, now partly ruinous, with remains of the outer walls of the palas and the ring wall. Its 14th-century bergfried is a 27-metre round tower with a conical roof and battlements, its walls 3.45 metres thick at the base. North of it, the inhabited three-winged castle from the 15th century encloses a trapezoidal courtyard closed by a large Gothic gate, from which a bridge crosses the deep neck ditch.

The castle was first documented in 1145 and played an important role as a fortress along a medieval trade route. A major fire in 1654 destroyed large sections, prompting reconstruction of a residential area between 1664 and 1665.

The name Wildberg combines Middle High German 'wilt' (wild or game) with 'bërc' (mountain), describing a wild mountain or one rich in game. Adalbert Stifter set his 1830 fragment 'Julius' at the castle and mentions it in 'Der Waldgänger'. Since 1984 the Kulturverein Schloss Wildberg has used the castle for artistic events.

The ruins are situated on private property of the Starhemberg family and are not freely accessible. Visits are only possible during special cultural events held throughout the year.

Wenceslaus IV was seized by rebellious Bohemian nobles in Prague and handed to Kaspar and Gundaker von Starhemberg on 5 July 1394; they locked him in a tower room at Wildberg. Under pressure from German princes he was released on 1 August 1394, after barely four weeks.