From the former castle still stands the imposing tower today.
Haslach Castle

Haslach Castle is located in Haslach an der Mühl in Upper Austria. Of the original complex, a tower remains today, serving a dual function.
History+
The construction of Haslach Castle dates back to Peter von Rosenberg. The fortification of the market town of Haslach was a point of contention between the Rosenbergs, the Bishops of Passau, and the respective sovereign. In 1341, Peter von Rosenberg committed in a repurchase agreement with Bishop Albert of Passau to dismantle the fortress he had built in the market. It is unclear whether this was fully implemented, but the tower remained standing. In 1487, Emperor Frederick III ordered Wok von Rosenberg to cease construction work on the market and castle fortifications, as permission was lacking and there was no necessity. In 1599, Peter Wok von Rosenberg sold Haslach to Bishop Leopold of Passau.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Haslach_an_der_M%C3%BChl_%28Wehrturm-1%29.jpg
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 48.5744, 14.0410