The Ancient Settlement of Bjni is situated on both banks of the River Hrazdan 13 km southwest of Hrazdan, the regional center of Kotayk Marz of the Republic of Armenia. One of the notable fortresses, Bjni medieval fortress is located on the eastern side of the village. As a separate unit (state index 6.19.1) it is included in the state list of immovable monuments of history and culture, considered as state-owned property of the Republic of Armenia and is not subject to alienation and is in the care of the “Service for the Protection of Historical Environment and Cultural Museum-Reservations” SNCO of the RA Ministry of Education, Science, Culture and Sports. Bjni Fortress is divided into two parts Mets /Upper/ Berd (Great Fortress) (state index 6.19.1.1) which consists of the following monuments: Surb (St.) Khach church (state index 6.19.1.1.1) – IX-X centuries, Cistern (state index 6.19.1.2)- X century, Palace (state index 6.19.1.3)- X century and Storin Berd (Lower Fortress) (state index 6.19.2.1)- X-XV centuries, secret passage (state index 6.19.1.3)- X century, industrial and habitable multi-story complexes, still partially excavated monumental secular building built of hewn stones. The conservation area of Bjni ancient site is 17.5 hectares, while the castle itself is 7.0,6 hectares.
The first archaeological excavations in Bjni were carried out in 1928. A fragment of an Urartian cuneiform inscription was found in Bjni at that time or a year later. On the same promontory there is also a vast Cyclopean fortress on the territory of which cultural traces date back to the Early Bronze Age including the Antiquity. As a result of the excavations carried out in 1977-1978 were unearthed the main walls of the central cupola’d cruciform church Surb Khach (St. Khach) (IX-X centuries), the cistern, the secret passage, the vaulted palace building consisting of two halls and a refectory, details of the secular and religious buildings of the early medieval church, many small and yet unexcavated rooms visible on the surface and residential houses. During the excavations in the territory of the medieval castle in 2002-2007 fragments of black lacquered pottery of the I century BC have been excavated which suggests that the medieval castle was inhabited at least in Antiquity. Bjni fortress, one of the most famous structures of the medieval castle constructions, is located here. It is situated on the right bank of the River Hrazdan, on the eastern side of the village. In 2007-2008 the walls of the castle, the foundations of the secular buildings, the adjacent structure and the churches were restored, the reservoir and the beginning of the underground passage were strengthened.