Laleli social complex includes mosque, madrasah, Turkish bath,  poorhouse and fountain and Sultan Mustafa the 3rd made it built in 1760-1764. After his death, the tomb was added to the complex. Designed in a baroque and classical style, it is one of the first buildings in western style in Ottoman architecture. Laleli mosque is one of the most outstanding buildings in the social complex. The mosque which has 105 windows is one of the most extraordinary buildings in Ottoman architecture.