Tourism in Turkey important tourism spots not only in Turkey but also in the world. There are thousands of hotels and other tourist-oriented industries in the city, catering to both vacationers and visiting professionals. Turkey's largest city and metropolis and a leading global city, Istanbul, has a number of major attractions derived from its historical status as capital of the Byzantine and Ottoman Empires. These include the Sultan Ahmed Mosque (the "Blue Mosque"), the Hagia Sophia, the Topkapı Palace, the Basilica Cistern, the Dolmabahçe Palace, the Galata Tower, the Grand Bazaar, the Spice Bazaar, and the Pera Palace Hotel. Istanbul has also recently
Turkey aged 65 years or older make up 7.3 percent. In 1927, when the first official census was recorded in the Republic of Turkey, the population was 13.6 million. The largest city in Turkey, Istanbul, is also the largest city in Europe in population, and the third-largest city in Europe in terms of size. Article 66 of the Turkish Constitution defines a "Turk" as "anyone who is bound to the Turkish state through the bond of citizenship"; therefore, the legal use of the term "Turkish" as a citizen of Turkey is different from the ethnic definition. However, the majority of the