Belogradchik Fortress

The Belogradchik Fortress, also known as Kaleto, is an ancient fortress located on the north slopes of the Balkan Mountains, close to the northwestern Bulgarian town of Belogradchik and is the town's primary cultural and historical tourist attraction, drawing, together with the Belogradchik Rocks, the main flow of tourists into the region. It is one of the best-preserved strongholds in Bulgaria and a cultural monument of national importance.

The fortress's walls are over 2 metres thick in the foundation and reaching up to 12 m in height. Three separate fortified yards exist that are connected with each other through gates. The fortress has a total area of 10,210 square metres. The Belogradchik Fortress was reconstructed to later become a proclaimed cultural monument. It is managed by the local historical museum authority.

Source: Wikipedia