Underground Built Heritage (UBH) is a unique cultural and tourist resource, often with diverse values for tourists and the local community. The research on UBH requires an interdisciplinary approach, various techniques, and methodologies, with current literature mainly focusing on sustainability and conservation issues of these sites, their classification and definitions. This paper tends to fill in the research gap in this field, which is based on the fact that tourism and marketing issues in research of UBH are quite rare and often neglected, although such aspects are very important for heritage valorization. Thus, the principal aim of the paper is to explore how heritage image, perceived authenticity, and perceived value affect motivation to visit UHS (Underground Heritage Sites) and domestic visitors’ loyalty. To explore this aim, the survey was conducted in five countries (Serbia, Poland, Bulgaria, Turkey, and Albania,) on five underground heritage sites. The study sample included 504 domestic visitors (residents of the country where the research was conducted) of underground heritage sites—Petrovaradian Fortress Military Galleries (Serbia), the Srebrna Góra Fortress (Poland), Roman City (Bulgaria), Göreme (Turkey), and BUNK’ART (Albania). The results show a significant positive influence of perceived authenticity on perceived value, heritage image, motivation to visit UBH sites, and loyalty. However, perceived value seems to be a stronger predictor of all analyzed constructs. Heritage image also showed significant positive effects on motivation to visit and loyalty. Theoretical and practical implications of results are discussed in the paper.