Built on the site of a temple during the Roman period, Kesik Minaret functioned as a mosque for 400 years after being used as a church for 1000 years. Today, it is registered as a cultural asset and continues to be used as a mosque while welcoming visitors as a museum. The building, where spolia materials from the Roman and Hellenistic Periods were used, was restructured in order to be converted into a mosque during the Ottoman Period. With the present museum-mosque concept, it is now both a museum where tourists are able to visit and a building open to worship. However, the fact that it was built using spolia materials, converted from a church, and ultimately used as a museum-mosque, is in conflict with the sanctity of worship and therefore the sanctity of the mosque; moreover, since it is in active use, it becomes very difficult to preserve it as cultural heritage. Therefore, this study is shaped by a discussion on the concept of the sacred and sacred space through the example of Kesik Minaret. After arriving at a definition of sacred space based on the arguments of Otto, Durkheim, and Eliade this discussion deals with the definitions of sacred space in Islam. This interdisciplinary study, which we have prepared as researchers from the fields of architecture and philosophy, examines the sanctity of Kesik Minaret, which was converted from a church to a mosque, based on the Qur'an and the hadiths, and presents the definition of archaeo-space as a new concept for such structures.