Burg Westernhagen, Medieval castle ruins in Berlingerode, Germany.

Burg Westernhagen is a vanished lowland castle, of which a 32 by 20 metre mound and a seven metre wide ditch remain, on a 250 metre high site in the Rangental valley southeast of Berlingerode. A sunken path leads up from the Eichbach valley, and the ditch separates the mound from the slope of the Birkenberg.

The fortress was built in the 12th century as a seat of the von Westernhagen family and was destroyed during the Peasants' War of 1525. It was never rebuilt after this destruction and gradually fell into ruins.

The name Westernhagen comes from the noble family that built the castle in the 12th century. A branch living east of the castle was recorded in 1484 as "Henricus de Indagine orientali" and proposed a priest for Berlingerode's church. The family held the castle as a fief from Quedlinburg Abbey and later from Mainz; after 1525 the lords moved to their manor seats in Teistungen and Berlingerode.

The site is reached via a sunken path from the Eichbach valley below, which follows the contours of the old fortifications. It is best to wear sturdy footwear and expect muddy conditions, especially where the former ditch still holds water.

West of the castle mound lay the deserted village of Westernhagen, whose church with the St. Catherine altar is documented in 1370 and 1391; 28 farmsteads (mansi) were counted there in 1420. The settlement and castle were named together as a fief of Quedlinburg Abbey in 1483/84, held by the counts of Regenstein, with the lords of Westernhagen as under-tenants.