Burg Honberg, Medieval castle ruins in Tuttlingen, Germany

Burg Honberg is the ruin of a late-medieval fortress on the Honberg hill at 739 metres above sea level, overlooking Tuttlingen and the Danube valley. It was never a castle in the strict sense but a fortification, built from 1460/1470. Two towers were rebuilt in the 19th century with donations, not in their original form, and stretches of the defensive wall still stand.

Count Eberhard im Bart built the fortress between 1460 and 1470 as part of Württemberg's regional defences. When he became the first Duke of Württemberg on 21 July 1495, Honberg was the main military structure in the south of the new duchy. In 1645, during the Thirty Years' War, the garrison destroyed it to its foundations on the orders of Konrad Widerholt, commander of Hohentwiel; the written order is said to have been affixed to one of the towers. Some historians instead date its ruin to the Battle of Tuttlingen on 24 November 1643, when it had served as the Franco-Weimarian headquarters.

The name Honberg-Sommer comes from the hill itself. Each summer the ruins host this tent music festival for over two weeks, with the stage set inside the fortress walls. Occasionally the grounds also host medieval markets and local association concerts.

The ruins sit on the Honberg hill at 739 metres, roughly 100 metres above the Danube and the town centre of Tuttlingen. Paths climb from the town to the walls and the two rebuilt towers. The site is open ground with uneven stone surfaces, so sturdy shoes help; the terrain limits wheelchair access in places.

The written destruction order issued by Konrad Widerholt, commander of Hohentwiel, is still affixed to one of the towers, stating that the fortress was razed in 1645 to protect Tuttlingen from the approaching enemy. Some historians instead place its ruin at the Battle of Tuttlingen on 24 November 1643, when the fort served as the Franco-Weimarian headquarters.