Büyükada Postal Codes: 34970 | Adalar, İstanbul, Marmara

Key Facts

Büyükada is the largest and most prominent of the nine islands comprising the Adalar district of Istanbul, Turkey. Located in the Sea of Marmara, approximately 20 kilometers southeast of central Istanbul, this island serves as the administrative center for the entire Princes' Islands archipelago. With a land area of about 5.4 square kilometers, Büyükada features a distinctive geography characterized by two prominent hills—Yücetepe (202 meters) and İsa Tepesi (164 meters)—connected by a narrow isthmus. The island has a permanent population of approximately 7,500 residents, though this number swells significantly during summer months when it becomes a popular weekend and holiday destination for Istanbul residents seeking respite from the city's bustle. Büyükada is divided into two main neighborhoods—Nizam and Maden—and is renowned for its strict ban on motor vehicles, with transportation limited to bicycles, horse-drawn carriages, and electric service vehicles. The island's architectural landscape is dominated by historic wooden mansions, Ottoman-era buildings, and religious structures including the Saint George Monastery. As the principal island of the Adalar district, Büyükada serves as the gateway for accessing postal code information and administrative services for all the Princes' Islands.