Research by Ivan Fedorovich Nikitinsky is devoted to the analysis of unique historical and cultural monuments of the medieval inhabitants of Verkhnyaya Kokshenga. This local group of the North Russian population - kokshars - with their sacred groves and sanctuary is inherent in an original version of Old Russian culture. In the process of acquaintance with the text and illustrations, the reader discovers new components that form the basis of the religious and, as the author believes, proto-scientific worldview of the kokshars of the 15th century. This worldview, like the annual economic cycle, is reflected in the structure and petroglyphs of the Tiunovsky sanctuary.