Schloss Oberwinzer, Medieval castle ruin in Winzer, Germany.

Schloss Oberwinzer is a medieval castle ruin on elevated terrain in Winzer with stone walls and foundations still visible today. The remains display typical medieval construction methods with varying stone sizes and clear traces of earlier fortification structures.

The castle was founded in the medieval period and served nobles as both a residence and fortified stronghold in the region. Gradual decay over centuries led to its current state as a ruin.

The name Winzer comes from the village below, first recorded in a 1005 deed; the castle was built by the Winzerer family, who took their name from it and died out in 1324. Visitors can still see round arches from a 19th-century restoration, and the site is protected as a landscape-defining monument.

The ruin stands on the Schlossberg hill at 347.6 m, reached on foot from the market of Winzer; the climb is short but the ground is uneven. Remains of the ring walls and two tower stumps survive up to about eight metres high, and the site is freely accessible. Sturdy shoes are advisable, and the two section ditches in front of the walls are easy to miss.

The ruin was blown up on 1 November 1744 by Hungarian hussars under the Pandur leader Franz Freiherr von der Trenck during the War of the Austrian Succession. In the 19th century its stones were quarried away, until King Ludwig I placed the remains under protection.