Although the watercolours and pen drawings of still existing and already lost architectural buildings created by K. F. Bogaevskii in the 1920s are more modest than his pictures, they still form the golden collection of the Crimean past. The sketches of architectural monuments are a specific part of the painter’s heritage, which certainly made an impact on the development of his creative approach to the Crimean landscape, were the job he did by an order from the institution responsible for all cultural heritage in the region, or the Crimean Department for the Museum Affairs and Protection of the Sites of Art, Past, Nature, and People’s Daily Life (KrymOKHRIS). This paper presents K. F. Bogaevskii’s watercolours discovered in the collection of the Bakhchisarai Historical, Cultural, and Archaeological Museum Preserve and I. K. Aivazovskii Feodosiia Art Gallery: they show mediaeval monuments located in the south-eastern suburbs of Bakhchisarai, Salachik, and Chufut-Kale. The art historical analysis of these works has been done; the history of their creation has been explored. The author underlines the significance of these drawings for the scholarly studies of the cultural heritage sites of Bakhchisarai, reconstruction of their authentic appearance, localization and identification, and the studies in the cultural heritage site protection works in the Crimea in the 1920s. Artistic value of the painter’s works under analysis is beyond any doubt: the precision of drawing, reproduction of architectonics of buildings, necessary details of pictures were caused by the task and corresponded to K. F. Bogaevskii’s high professional attitude to works. The watercolours and drawings create an artistic image of the monuments with the composition incorporated into the existing natural setting. K. F. Bogaevskii was a landscape painter, a master with academic education, who passed through A. I. Kuindzhi’s school.