The so-called "Sanctuary" also known as the catacomb of St. John the Baptist is a historical listed monument of Thessaloniki located southeast of the Temple of the God of Wisdom at the junction of Mackenzie Kig Street with the pedestrian street of Iktinos It is a nave built in the early 19th century partly on the ruins of an earlier building with an underground arcade, annexing to the courtyard of the building the architectural remains of a hexagonal building known in the literature as the nymphaeum of the Roman period or the Early Christian baptistery. The completion of the project will facilitate access to the monument for people with disabilities and other categories of people with disabilities and will solve the long-standing problem of universal access by all visitors to the archaeological site and the church that functions as a parish church.