Built in 537 AD at the beginning of the Middle Ages, it was famous in particular for its massive dome. It was the world's largest building and an engineering marvel of its time. It was the largest pendentive dome in the world until the completion of St. Peter's Basilica.
One of the largest and oldest covered markets in the world, with 61 covered streets and over 4,000 shops which attract between 250,000 and 400,000 visitors daily. In 2014, it was listed No.1 among the world's most-visited tourist attractions with 91,250,000 annual visitors. The Grand Bazar at Istanbul is often regarded as one of the first shopping malls of the world.