The present diploma thesis proposes the use of digital technologies for the development of a cultural heritage application, in the form of a game, which utilizes interactive storytelling as a tool, and aims to highlight the first ancient theater of Larissa. By studying the archaeological site and using techniques such as augmented reality, different perspectives of the theater are explored, and this cultural object is redefined. More specifically, an interactive environment is created through the design of an augmented reality application, which runs in-situ. It is a game which constitutes a linear suggestion of a tour of six points in the archaeological site of the theater. Narratively following the ancient dramatic scheme "hubris, ate, nemesis, tisis, catharsis", the ancient Greek theater as an institution is explored, as well as the first ancient theater of Larissa and the ancient festival of the Eleftheria, which took place at this location. The reference to Eleftheria, which is utilized narratively, revives and preserves the intangible cultural heritage of the theater. The specific object of cultural heritage was chosen because, as it has not yet been completely revealed, it continually engages the public of the city, demonstrating a remarkable range of cultural heritage with potential for development, while at the same time it is the most representative landmark of the city. Questions are also raised regarding the ability of the narrative element to serve as a useful tool for the projection of cultural heritage, but also questions regarding the approach to the design of the augmented space as an architectural problem. By combining the viewing of sites of cultural importance with the use of augmented reality, new ways of knowledge and new spatial extensions are created, and the cultural experience of the viewer-participant is redefined. Ultimately, the narrative rendered through the interaction and the very participation and willingness of the user, leads the theater to acquire a new experiential character, modern and changeable.