A unique medieval monastery is being excavated 22km north Kurdjali, in southern Bulgaria. From the 10th to the 14th century it was part of the famous town of Hyperperakion.

The ruins of the basilica are preserved a meter and a half underground, according to the main excavator, professor Nikolai Ovcharov. Its floor is covered by a marble mosaic in the opus sectile style (Acanthite) that has been preserved in perfect condition. The Romans often paved the floors of their houses and public buildings in the same way as they paved the monastery of Hyperperakion with the technique known as opus sectile. The small, coloured cubes of marble would have been cut with a knife, according to professor Ovcharov. The mosaics depicted various scenes which formed part of a life cycle. "We were aware that this mosaic existed in King Simeon's kingdoms but we have never come across remnants of it," Ovcharov said.

The main basilica is surrounded by other rooms including a tomb-like church with a sarcophagus. The expedition discovered the remains of a Byzantium bishop in the sarcophagus. "Unfortunately there are no signs around the sarcophagus so it's hard to name him," said Ovcharov. The expedition found several lead seals used by famous dignitaries in the 10th and 12th centuries. The archaeologists displayed the basilica's seal, which is made of black onyx and features Archangel Michail.

In past centuries the region around Kurdjali was a centre of national and international power. It was there, in the sacred Thracian Palace of Perpericon, that Alexander the Great gained his faith to conquer the world. The palace and its fortress were the capital of the Odris Kingdom, the strongest state of the Thracians.

During the Roman Empire the noblemen and army officers used the region for rest and recreation. The best examples of its facilities are the well-preserved villa Armira in Ivailovgrad and the ancient town of Perperikon (which became Hyperperperikon in the Middle Ages). A huge king's palace has also been discovered at the site and there is a sanctuary on the same hill dating back to the third and fourth centuries BC. "This was a place of conflict between Byzantium and Bulgaria. It remained the border between the two countries for quite a while," said Ovcharov.

During the Byzantine Empire the region was a Christian fortress. The Monastery of Joan Prodrome is a typical example. Archeologists have proved that it was the base of one of the most powerful Archbishops in Byzantine. According to some scholars the famous army leader Belizarius was born in Ivailovgrad. After the foundation of the Bulgarian state in 681 AD the Rhodope Mountains became the frontier between the two rival states. Many fortresses including those at Ustra, Perpericon, Efrem and Vishegrad were destroyed and there were numerous wars and sieges.

The Crusade or Roman Empire was a strong influence on the region of Kurdjali. For some time the region was the scene of struggles between Bulgarians, Romans and Byzantines. There is historical evidence that the famous battle between the Bulgarian king Kalojan and Roman Emperor Baldwin took place somewhere in the eastern part of the mountains.

The formidable fortress of Monjak was the crusaders' stronghold and the point from which most of their expeditions started. That period lasted for almost two centuries and ended with the Turkish invasion of the Balkan Peninsula. The remains of a great number of fortresses, castles and monasteries in the Kurdjali region are evidence of that romantic and legendary epoch.

When they were absorbed into the Turkish Empire, the Rhodope Mountains ceased to play an active political role in the region. During that period many buildings, roads and bridges were created but the remains of the turbulent centuries that preceded them have been preserved and are now visited by thousands of people.