Mediterranean Basin is one of the oldest settlement areas in the world with its 9000 years of history. The interaction between societies, which got even stronger with the organized trade routes in the area, is the most characteristic property of the Mediterranean Basin. The Aegean and Mediterranean shores of Anatolia witnessed the shared lives of Turkish-Muslims, Greek-Orthodox, and even the Italians for more than 500 years. That's why it is possible to call this area, as "interference zone" or "transition region".One of the areas that is located on Anatolia's interference zone is Datça Peninsula. This thesis is conducted over the vernacular building stock that was built in the peninsula from the 19th century to mid 20th century. The settlements of Çeşme District and Yaka Village, are comprehended in this thesis. One roomed living units are named as main units. Main units and its fireplaces were examined. The tables, that show the size and location of the fireplace, were constituted. Analysises were done over these tables. The aim is to document the building stock in this area and to analyse on the fireplace. Consequently, it was discovered that the main units have clues belonging to Turkish Room, such as seki üstü / seki altı. It was also understood that the fireplace is the pre-condition of identifying the unit as living space.