1 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.

The initial fortress was constructed during the Roman Empire, taking advantage of the natural rock formations in the area. Initially, the Belogradchik Fortress served for surveillance and not strictly defense. Bulgarian tsar of Vidin Ivan Stratsimir extended the old fortress in the 14th century, building fortified garrisons in front of the existing rock massifs. During Stratsimir’s rule, the Belogradchik Fortress became one of the most important strongholds in the region, second only to the tsar’s capital fortress of Vidin, Baba Vida.

During the Ottoman conquest of Bulgaria, the fortress was captured by the Ottomans in 1396.

2 Baba Vida

Baba Vida is a medieval fortress in Vidin in northwestern Bulgaria. It consists of two concentric curtain walls and nine towers of which three are preserved to their original full medieval height. The construction of the fortress began in the 10th century at the site of the Roman castell Bononia.

The fortress played a role during the Ottoman rule of Bulgaria, serving as a weapon warehouse and a prison, also as residence for Osman Pazvantoğlu.

3 Asen’s Fortress

Asen’s Fortress is a medieval castle in the Bulgarian Rhodope Mountains, 2 to 3 kilometres (1.2 to 1.9 mi) south of the town of Asenovgrad on a high rocky ridge on the banks of the Asenitsa River.

The earliest archaeological findings date from the time of the Thracians, the area of the fortress being also inhabited during the Ancient Roman and Early Byzantine period. The fortress gained importance in the Middle Ages, first mentioned in the statute of the Bachkovo Monastery as Petrich in the 11th century.

4 Mezek

The Mezek Fortress is claimed to be among the best preserved Bulgarian medieval castles. It dates to the 11th century. Along with the discovery of adjacent Thracian tombs, it was studied by a team under archaeologist Bogdan Filov in 1931–1932. The castle has nine towers, five of which lie at the vulnerable south wall. The Mezek Fortress was built out of stone, with two decorative lines of bricks on the outside. It suffered some destruction around 1900, when stones from the fortress were used for the construction of Ottoman barracks in Svilengrad.

5 Tsarevets (fortress)

Tsarevets is a medieval stronghold located on a hill with the same name in Veliko Tarnovo in northern Bulgaria. Tsarevets is 206 metres (676 ft) above sea level. It served as the Second Bulgarian Empire’s primary fortress and strongest bulwark from 1185 to 1393, housing the royal and the patriarchal palaces. It has three entrances. The main entrance is located in the easternmost side of the hill. The castle complex is located in the centre, surrounded by an internal stone wall, two battle towers and two entrances – north and south. It consists of a throne hall, castle church and the king’s chamber. The restoration of the fortress Tsarevets began in 1930 and was completed in 1981 in honour of the 1300 anniversary from the establishment of the Bulgarian state.

6 – Nesebar

The first fortifications of Nesebar, the ancient Messembria, were constructed in the 8th century BC. They were improved by the Ancient Greeks in the 5-4th century BC, and subsequently by the Byzantines in the 5th century AD. In the Middle Ages the city often changed hands between the Bulgarian and the Byzantine Empires and the fortifications were frequently reconstructed. The last reconstruction was in the 14th century by Emperor Ivan Alexander of Bulgaria.

7 – Ovech fortress

During the Middle Ages Ovech was a key centre of the First Bulgarian Empire with an important monastery at the modern village of Ravna and a major scriptorium of the Preslav Literary School. During the Uprising of Ivaylo the rebel leader and subsequently emperor of Bulgaria Ivaylo defeated a 10,000-strong Byzantine army near the city in 1279. During the Second Bulgarian Empire Ovech was the seat of a metropolitan in the 14th century. Ovech was captured by the Ottomans in 1388 after a long siege.

8 – Ustra castle

Ustra is a castle in the eastern Rhodope Mountains in southern Bulgaria. Its ruins lie 4 kilometres (2.5 mi) south-west of the village of Ustren situated on a hill at approximately 800 metres (2,600 ft) above sea level. The fortress was built in the 10th century AD to protect an important trade route. It was taken by the armies of Simeon the Great (r. 893-927), but after his death, it was among the lands given back to Byzantium in return for recognition of the imperial title of the Bulgarian rulers. Between the 12th and 14th centuries, it frequently changed hands between the two empires, but the Byzantines held it most of the time.

9 – Shumen fortress

The origin of the Shumen fortress can be traced to the early Iron Age and was later owned by the Thracians in the 5th century BC. From 2nd to 4th centuries AD, it was controlled by the Romans who built towers and walls, and it was refurbished by the Byzantines as a garrison town. Shumen thrived in the Middle Ages as an important stronghold of the Bulgarian Empire. In 1444 it was destroyed by the Ottomans after their victory in the Battle of Varna over a Christian army under Władysław III of Poland. The fortress remained deserted ever since.

10 – Peristera

Peristera is a fortress dated from the Late Antiquity and the Middle Ages situated in the Rhodope Mountains near the town of Peshtera in Pazardzhik Province. Peristera had three lines of defensive walls and six towers. It was destroyed by the Ottoman invaders in the 14th century.