The imaging method based on the absorption and scattering of atmospheric muons (muography method) uses the natural flow of muons formed in the interactions of cosmic rays in the atmosphere. The method is at the junction of elementary particle physics and research in other very diverse fields of natural science, in particular, in archaeology. The paper presents the first results of an experiment to study a unique underground structure in the Holy Dormition Pskov-Caves Monastery, which is a cultural object with a centuries-old history. [ABSTRACT FROM AUTHOR]