Ruins of the medieval town-fortress Hotalich are located 4km north-west from the today`s town of Sevlievo. The fortress was built by the Byzantines in the 5th century. In 10th century, at the same location, the Bulgarian state began construction of defense facilities to defend the country from the barbarian invasions from the north and Byzantium from the south.
The fortress was the largest in area except these of the old Bulgarian capitals Pliska, Preslav and Veliko Tarnovo.The excavations of medieval town of Hotalich and the fortress began for the first time in 1981. The archaeologists were found a high tower, two parallel walls (first of them dates back to the Early Byzantine period and the second from the 9th-10th century), remains of two main gates, ruins of quarters, churches, palace of the boyar (the local ruler), etc.
References:Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.