Late Chalcolithic and the Transitional Period into the Early Bronze Age (3500-3000 BC)

            The Late Chalcolithic Period deposit at the very lowest layer has been excavated in a limited area in the western sector of the mound. The settlement plan of the Transitional Period into the Early Bronze Age is characterised by a zigzag-running defensive wall encircling the settlement; the backs of houses are abutted to the defensive wall and the front of the houses open onto a central court. This layout is of utmost importance in terms of exhibiting a possible prototype of the Anatolian Settlement Plan (Anatolisches Siedlungsschema) or “Inland Western Anatolian Settlement Plan”. The walls of the houses are sometimes protected almost    up to the roof. The pottery of this period gradually gains EBA characteristics.


             The Early Bronze Age I (3000-2700BC)

            Soundings have been dug in certain parts of the mound in connection with this period and remnants of walls have been exposed during these operations. Excavations carried out in wider areas in the fields to the SE yielded single- or double-roomed long-houses (row-houses) built adjacent to each other, dating to the end-phase of this period.


             The Early Bronze Age II (2700-2400 BC)

             The settlement plan represented by six architectural phases at Küllüoba was set out in a cornered rather than radial plan. It is generally comprised of adjacent long-houses arranged in a row encircling the courtyards, which are of different shapes and sizes. The fronts of these houses open onto the courtyard. In this period we can speak of lower and upper settlements:


         - The Upper Settlement is encircled by an enclosure wall on which four main and two subsidiary gates have been exposed thus far. In the eastern section of the Upper Settlement there is an enclosed architectural unit, known as Complex I, with a courtyard (measuring 20 X 25 m) encircled by houses. Another courtyard, this time much larger, encircled by long-houses, is located in the western section of the Upper Settlement. A large building complex called Complex II, (measuring 31 X 24 m), and a trapezoidal building (15 m in length) are found in this courtyard. Complex II has a monumental megaron in the south and four architectural units adjacent to it in the north.

        - Remnants of houses in the Lower Settlement have also been excavated outside the enclosure wall of the Upper Settlement. Some of these have been excavated to the west and southwest of the Upper Settlement; they are long-houses that are attached from the back to the enclosure wall of the Upper Settlement. Independent houses with simple plans and flimsy walls have also been exposed in the fields to the southeast.


            During the Early Bronze Age II at Küllüoba the gradual emergence of lower and upper settlements and free-standing building complexes of possible administrative function provide a new insight into the emergence and development of urbanism throughout Western Anatolia. Furthermore, this excavation has provided important information on the characteristics, development and interrelations of the “Upper Sakarya Pottery Group” in which Küllüoba is also situated.

            The Early Bronze Age III Period (2400-1900 BC)

            The phases of the Early Bronze Age III Period at Küllüoba have been established superimposed in Grids Z 19 and AA 19. This shows that there is at least an early EB III with three phases, on top of which is a late EB III (Transitional Period into the Middle Bronze Age) with five phases. The total thickness of both periods reaches almost 5.0 m.

            The EB III investigations at the mound yielded important evidence on the trade relations established between Syro-Cilicia and the North Aegean over inland Northwestern Anatolia and its influence on the cultural/political development of the region. Parallel to this event, detailed information has been obtained at the site regarding the emergence of new wares and forms in pottery in particular, as well as the characteristics of early wheel-made pottery. Important information on late EB III architecture has also been gathered from the Küllüoba excavations, with evidence that single or multi-roomed houses were built independently. Furthermore, abundant stratified pottery  has been recovered from this period. In this period, the Eskişehir region and its immediate vicinity split from the west and bonded culturally and politically with Central Anatolia. A lead idol from this period is one of the most important finds recovered so far at Küllüoba. Since 2019 excavations was also started in the cemetery of the settlement. The finds collected in the Küllüoba excavations are kept and displayed in the Eskişehir Archaeological Museum.


            The artifacts found during the Küllüoba Excavation are preserved and exhibited in the Eskişehir Archeology Museum. Apart from the contributions of the General Directorate of Cultural Heritage and Museums, Bilecik Şeyh Edebali University and the Turkish Historical Society, Knauf Insulation Turkey has become the main sponsor of the Küllüoba Excavations, with the protocol signed as of 2021.