Istanbul or Constantinople is Turkey's largest city and its cultural and economic center. This city is located next to the Bosphorus and the Sea of Marmara. The Strait of Bosphorus separates both continents from Asia and Europe, and Istanbul is the only major city in the world, located on two continents. The natural harbor of the Golden Horn or the Bay is located in this city.
This metropolis was chosen as the capital of European culture in 2010. In terms of the number of foreign tourists, the world's third-largest tourist city.
When the Turkish Republic was formed in 1923, its capital was changed from Istanbul to Ankara. But Istanbul retained its core as Turkey's commercial and industrial center and is now Turkey's largest city.
The vast majority of people across Turkey and in Istanbul are Muslims, and in particular Sunni people.
Istanbul has always been the center of economic life of the country, due to the international connections between land and sea border routes. It accounts for about 20% of Turkey's industrial work and 38% of Turkey's industrial space. In addition, 55 percent of Turkey's products are from trade and trade, and 45 percent of the country's trade comes from wholesale and 21.2 percent of Turkish products from national mass products. 40% of taxes collected in Turkey and 27.5% of Turkish national products. By 1980, Istanbul's gross domestic product (GDP) grew by an average of 5% a year.