The main character of the article is Jan Kochanowski, a naturalist from Grodno. His personality was of particular importance for the history of this city in the interwar period, primarily because of his scholar activity in the field of natural science and his social-minded position in public life. In October 1942 Kochanowski was killed by the Nazis, when he had offered his life in exchange for the life of his friend, who was taken as a hostage. However, Jan Kochanowski’s activity has wider dimension. Within his lively participation the Botanical Garden in Grodno was established in 1925, and one year later the Municipal Museum of Natural History was open for attendance. Jan Kochanowski devoted much energy and attention to research and popularize local lore knowledge. This naturalist from Grodno was investigating the regional places associated with the history of the country and some areas characterized by unusual and extraordinary natural phenomena. The name of Kochanowski stands also among initiators of many regional publications and co-editor of the journal "Niemen" (1935-1939). Teaching activity and studying local lore were combined with zealous idea of Kochanowski to protect natural artifacts of the region. Honoured resident of Grodno has played an incredible role in the dissemination of knowledge related to many peculiarities of nature so-called “Nadniemen” area (the territories closed to the Niemen). Owing to enthusiasm and activity of such personalities as Jan Kochanowski, in the interwar period Grodno was one of the most important centers of popularization of natural science and local lore in the region.