Burg Kollnburg, Medieval castle ruin in Kollnburg, Germany

Burg Kollnburg is a ruined hilltop castle west of Kollnburg's parish church at about 660 metres above sea level. Its surviving structures are a round bergfried 8.2 metres in diameter with two-metre-thick walls, the foundations of the palas, and a 17-metre-deep castle well.

The castle was first documented in 1153 as Chalnberch and served as a residence for local nobility. In 1468 it sustained major damage during a revolt against Duke Albert IV, beginning its decline into ruin.

The tower owes its survival to the Wald-Verein Viechtach, which bought it on 11 November 1895 and renovated it in 1912. The 11-metre tower now serves as an observation tower, and the ruin remains the property of the Bavarian Forest Association's Viechtach branch.

The ruin sits close to the parish church of Kollnburg and is accessible by foot paths. The hilltop location provides views over surrounding forests and the village, so sturdy footwear is recommended.

Many houses in the village were built using stones from the original castle walls, so medieval building materials live on in the modern village architecture. This reuse shows how the castle's resources were integrated into the local community.