Kardzhali (also Kardjali) is a province in southern Bulgaria, neighbouring Greece with the Greek prefectures of Xanthi and Rodhopi to the south and east. Kardzhali Province area is 3209 sq.km. The administrative center, the town of Kardzhali, is located in the low eastern part of Rhodope Mountains, on both banks of the Arda River between the Kardzhali Dam to the west and the Studen Kladenets dam to the east. The town is 260 km southeast of Sofia. It has a crossroad position from Thrace to the Aegean Sea — part of European transportation route 9. The area of Kardzhali has been inhabited since the Neolithic. Plenty of artifacts have been found during the archaeological excavations comprising ceramics and primitive tools. Most of them are now exhibited in the local museum of history. Later Thracian tribes settled in the area developing a highly advanced civilization. They built many sanctuaries dedicated to the gods of Sun and Earth. Near the village of Nenkovo (northwest of Kardzhali) an artificial cave was found in 2001. It has the form of a woman's womb. Exactly at noon, when the sun is highest on the sky, a ray of light comes in through a stone slit forming a falitic shade in the cave. According to the Thracian beliefs this is the conception of the new Sun god. This cave is considered a complex astronomic facility as the ray of light comes in the cave in a single day in the year. There are many stone castles and palaces the Thracians built in the region — Perperek, Ustra, Vishegrad. The most magnificent is Perperikon where a residence of a Thracian king was situated. The place is getting more popular as archaeological works are in progress and new artifacts are being discovered. During the Byzantine period Kardzhali was the centre of a Christian eparchy — Achridos. The Monastery of John the Precursor was built in the 6th-8th century and is now a monument of medieval architecture. The name Kardzhali is mentioned for the first time in Ottoman documents. It comes from the name of the Ottoman army leader Kardzha Ali, who conquered the region in the 14th century. Its old Bulgarian name, mentioned until the 17th century, was Žerkovo (Zherkovo). The town developed because of its position on the trade roads during the Ottoman rule. However, it remained a small town with almost no industry. During the 18th century Turkish brigands used this remote town as a hide-away and supply point, and the town was named after their leader. Kardzhali and its area became part of the autonomous province of Eastern Rumelia under the stipulations of the Berlin Congress of 1878, but after the reunification of the Principality of Bulgaria and Eastern Rumelia in 1885, was ceded back to the Ottoman Empire. Ottoman rule ended during the First Balkan War, with its liberation by the Bulgarian General Vasil Delov on 21 October 1912. The day has been celebrated yearly, since 1937, as a municipal holiday through concerts and commemorative events. Formerly Kardzhali was a tobacco processing center, but for economic reasons some of the communist era industrial plants are no longer operative. The large deposits of lead and zinc ore in the area make the town an attractive location for the metallurgy and machine building industry. Retail trade and services constitute the largest share of local production. The abundance of cultural and natural sights in the area also make it a promising area for tourism. Some of the most interesting sightseeing places are the Thracian town of Perperikon - located near the city Kardzhali on a rock high above the valley. It is interesting for the fact that it is cut in the rock and represents the period of highest achievements and power of the Thracians. The monastery of John the Precursor from 11th century - located in the Vesselchane Quarter of the town. It was renovated in 2000 and a new bell tower was built. The Kardzhali Museum of History - one of the most extensive exhibitions in Southern Bulgaria. This includes pre-historic tools and ceramics from the Thracian cities of Perperikon and Tatul, Christian icons and ethnographic exhibits. It is located in the old konak (the Turkish town-hall built around 1870) with its period exterior architecture. Five kilometers from Kardzhali, near the village of Zimzelen, is a small badlands, where a series of white pillars have eroded out of the volcanic tuff which are referred to as the "Kardzhali Pyramids". Ensembles have been given names based on resemblances. One is known as "The Mushrooms" and another as the "Stone Wedding". There are two large dams on the Arda River. Studen Kladenez Dam is on the east and Kurdzhali Dam is on the west. The city is sandwiched between the two dams. Upper part of Studen Kladenez Dam is now up to the old bridge inside the city. The concrete wall of the Kurdzhali Dam is only about two kilometers upstream from this bridge. The reservoir of the Kurdzhali Dam was recently seeded artificially with European perch. The fish were taken from the Ovcharitsa dam. The first historical moment of the dam was in the 1970s, when it was artificially seeded with sheatfish. Nowadays there are 100 kg representatives. Later, 45,000 carp were introduced into the dam as well.