Formerly the three great empires of ancient times - the Roman Empire, the Byzantine Empire and the capital of the Ottoman Empire, with its excellent geographical location and rich cultural heritage, it combines the essence of the thoughts, culture and art of Europe, Asia and Africa. It has become an important meeting point of the Eastern and Western ideology and culture, leaving behind many long-standing historical sites. Its museums, churches, palaces, mosques, markets and wonderful natural scenery make people linger. The Sultan Ahmed Mosque was completed in 1616. Unlike the general mosque, it has six minarets. It is the only six-tower mosque that exists in the world. Because it is surrounded by more than 20,000 pieces of blue flower tiles, the light in the hall is extraordinarily soft and quiet, so it is also called "Blue Mosque". It is said that the craftsmen who burned these tiles were recruited from Persia, so it showed the relationship between Ottoman architecture and oriental architecture. It is regarded as the last large mosque building in the classical period of the Ottoman architecture and a masterpiece of architecture and art in the Ottoman era.