Büyükçekmece is a district and municipality (belediye) in the suburbs of Istanbul, Turkey on the Sea of Marmara coast of the European side, west of the city. It is largely an industrial area with a population of 380,000. The mayor is Hasan Akgün (CHP).
Istanbul (Turkish: İstanbul) is the largest city in Turkey, constituting the country's economic, cultural, and historical heart. With a population of 13.9 million, the city forms one of the largest urban agglomerations in Europe and is the third-largest city in the world by population within city limits. Istanbul's vast area of 5,343 square kilometers (2,063 sq mi) is coterminous with Istanbul Province, of which the city is the administrative capital. Istanbul is a transcontinental city, straddling the Bosphorus—one of the world's busiest waterways—in northwestern Turkey, between the Sea of Marmara and the Black Sea. Its commercial and historical center lies in Europe, while a third of its population lives in Asia.
Founded on the Sarayburnu promontory around 660 BC as Byzantium, the city now known as Istanbul developed to become one of the most significant cities in history. For nearly sixteen centuries following its reestablishment as Constantinople in 330 AD, it served as the capital of four empires: the Roman Empire (330–395), the Byzantine Empire (395–1204 and 1261–1453), the Latin Empire (1204–1261), and the Ottoman Empire (1453–1922). It was instrumental in the advancement of Christianity during Roman and Byzantine times, before the Ottomans conquered the city in 1453 and transformed it into an Islamic stronghold and the seat of the last caliphate. Although the Republic of Turkey established its capital in Ankara, palaces and imperial mosques still line Istanbul's hills as visible reminders of the city's previous central role.
An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side. A viaduct (a long bridge) may be made from a series of arches, although other more economical structures are typically used today.
Lake Büyükçekmece (Turkish: Büyükçekmece Gölü) is a liman, formed at the point, where the river Karasudere flows into the Marmara Sea. Located in the south of Çatalca district west of Istanbul, Turkey, it is used as a freshwater reservoir.
The lake's bar was reinforced in 1988 by a dam. The area of the lake is 28.47 km2 (10.99 sq mi), it is 7 km (4.3 mi) long and 2 km (1.2 mi) wide. The maximum depth is 8.6 m (28 ft) following deepening works carried out by the State Hydraulic Works.
The fluvial lake developed as the flow of Karasudere, coming down from Çatalca region, was blocked by the sandbank it created. A reedy, light salty water lake exists between the Büyükçekmece Dam and the Marmara Sea. Another lake of liman type, the Küçükçekmece Lake, is located around 12 km (7.5 mi) east of Büyükçekmece Lake.
The number of fish species known in the lake has decreased from 30 in the past to 15 nowadays.
A historical, 635 m (2,083 ft) long and 7.17 m (23.5 ft) wide multiple arch bridge, named after the Ottoman architect Mimar Sinan (1489-1588), spans the narrow opening at the bar connecting the lake to the sea.