Istanbul is the largest city of Turkey, and has the biggest population among European countries: as of 2013, 14 million. It is considered as the economic, cultural, and historical heart of the country. Istanbul is divided in two parts by the Bosphorus which connects not only the Sea of Marmara and the Black Sea, but also Europe and Asia. The city was named firstly Byzantium, then Constantinopolis, and lately Istanbul by Turks. Thanks to its strategic location and importance, four empires choose it as capital consecutively: the Roman Empire, the Byzantine Empire, the Latin Empire, and the Ottoman Empire. So, it carries the traces of different civilizations: churches, historical buildings, mosques, palaces, etc.
Hagia Sophia (Ayasofya ): Meaning “Holy Wisdom” in Greek, this building was firstly a Greek Orthodox church; it became a mosque after Constantinopolis was conquered by Sultan Mehmet II (1453), and lately was transformed into a museum. As the oldest cathedral, it ranks among the masterpieces of the world in terms of architecture. It was given the title of the world's largest cathedral until the construction of Seville Cathedral in Spain in 1520. With its large dome, it became the symbol of Byzantine architecture.
Sultan Ahmed Mosque (Sultan Ahmet Camii): It is one of the most important mosques of the Ottoman period. Built between 1609 and 1616, under the rule of Ahmed I., it consists of a complex of building (Külliye) where they are a “medrese” (religious school), a “darüşşifa” (hospice), and a tomb of its founder. This mosque has six minarets, one main dome and eight secondary domes.
Topkapi Palace (Topkapı Sarayı): A large Ottoman palace in Istanbul served as the primary residence of the Ottoman sultans for about 400 years, and transformed later into a museum. As it contains also some holy objects for the Muslims such as the Prophet Muhammad’s cloak and sword, it became an attraction center for tourists. It is part of Istanbul’s historic area included by UNESCO in the list of World Heritage Sites in 1985. Consisting of four main courtyards and various smaller buildings, the palace was inhabited at the Ottoman period by some 4,000 persons. It is Sultan Mehmet II, conqueror of Constantinople, who ordered in 1458 the construction of this palace which contains many buildings: mosques, hospital, bakeries, kitchens, etc.
Dolmabahçe Palace (Dolmabahçe Sarayı): Located in Beşiktaş on the European coastline of Bosphorus, and constructed by order of Sultan Abdülmecid I who had lived before with his family at the Topkapı Palace. It was used as the main administrative center by Ottoman Emperors during 44 years. Holding the title of the largest palace in Turkey, it consists of 285 rooms, 46 halls, 6 hammams, and 68 toilets. It has a mixed style of architecture: Rococo, Baroque, Neoclassical, and Ottoman.
Grand Bazaar (Kapalıçarşı): Located in the heart of Istanbul, it is one of the largest and oldest covered markets in the world: over 60 covered streets, and thousands of shops. It contained until recently five mosques, one school, 7 fountains, 10 wells, one fountain for ablutions (şadırvan), 24 doors, and 17 inns. It was built by Sultan Mehmet the Conqueror. The inner streets are covered with domes. You can find there famous handmade Turkish carpets and jewelry, gifts and decorative items made from copper, silver, bronze, as well as pottery and leather products. Hundreds of thousands of people come and visit it every day.