The lack of constitutional legislation for the protection of the built environment of the past — with its various contents — and its incorporation in the modern needs inevitably leads to the disappearance of the historic continuation and physiognomy of the Neohellenic cities. The limited interventions and the establishment of zones of historic monuments and archaeological sites are often the only solutions left. Some characteristic cases and experiences from the city of Thessaloniki and certain basic remarks presented in this article can be proven useful elsewhere.