The ruins of the castle are located on the southern outskirts of the village of Sredny (Transcarpathian region). The stone fortification was founded by the monastic order of the Knights Templar in the twelfth century.
According to historians, after 1312, the castle was owned by the monks of the Order of St. Paul, and even later — by the family of feudal lords Drugets, owners of the Uzhgorod castle. In the eighteenth century, the castle lost its strategic importance and gradually fell into decay. A distinctive feature of the castle is that its fortified base was only one square three-tiered tower-donjon measuring 19 x 19 meters. Its stone walls, lined with white-stone hewn blocks at the corners, reach a thickness of 2.5 to 3 meters. The entrance to the tower was carried out from the second level through wooden ladders, which were removed in case of a siege of the fortification. The first tier of the vaulted tower was used as a utility room; the two upper levels were for living. Internal stairs were used to communicate vertically between rooms..
Externally, the keep was surrounded by walls one meter thick, forming a square fortification with four corner towers and an entrance gate. The next line of defense consisted of an inner and outer earthen ramparts and a ditch between them. The general parameters of the entire fortification were 240 x 210 meters.
From the ancient castle to the present day, only the remains of the structures of the tower-donjon have survived..
The ruins of the castle are a unique monument of military architecture of the XII-XIII centuries, which represents an early type of fortification in the Ukrainian lands..