A Defense Structure in Tarsios Valley: Ergasteria (Kadıköy) Castle

Ergasteria (Kadıköy) Castle is located on a rocky hill at an altitude of 210 meters where the Kocaçay and Kadıköy streams, formerly known as Tarsios, intersect. The exact year of construction is unknown, but it was also used in the Byzantine Period. Today, it is approximately 2 km northeast of the Kadıköy neighborhood of the Balya District of Balıkesir Province. The castle has an advantageous location in terms of geographical and topographical features. The fact that the road from Erdek (Kyzikos) along Kocaçay (Tarsios) to Pergamon (Pergamon) via İvrindi increases its strategic importance. Strabon states that the road was cut many times by the Tarsios river. According to some sources, the valley of the Tarsios River (Kocaçay) was used as a route for the transportation of commercial products obtained from the mines and forests in the region to the Propontis (Marmara) coast, and Ergasteria was one of the important settlements in the region. In the 1990’s, the castle and its expansion area were associated with Ergasteria and the castle was registered under this name. The study examines the architectural characteristics of Ergasteria (Kadıköy) Castle and addresses concerns related to its preservation. In addition to the few studies conducted on the castle in the 19th and 20th centuries, the plan scheme, masonry and construction techniques were analyzed through on-site surveys and determinations. Based on the research findings, it has been determined that the plan scheme observed differs from those found in previous studies. During the research, 3 distinct masonry construction techniques were identified and analyzed for their similarities and differences. These studies were supported by up-to-date visuals and technical drawings in accordance with the measurements obtained during the fieldwork. At the conclusion of the study, top-scale conservation recommendations were presented for the conservation problems of Ergasteria (Kadıköy) Castle in order to maintain its structural integrity by preserving the structure, which is in the process of deterioration due to natural and human factors.