Petrich Kale Fortress sits on a high rock plateau towering approximately 100 meters near the village of Razdelna in the Varna region, about 4 kilometers north of Avren. The fortress was first established during the Early Byzantine period (5th-6th centuries AD) but was destroyed by the end of the 6th century, later rebuilt in the 11th-12th centuries as an important stronghold in the medieval Bulgarian defensive system. The fortress was finally destroyed by Ottoman forces on November 7, 1444, three days before the Battle of Varna. The site features remnants of inner and outer fortress walls and stone stairs carved into the rock, with historical connections to Bulgarian, Czech, Polish, and Hungarian medieval history.
