In a walking distance you can find major historical places such as blue mosque ( sultanahmet camii ) , hagia sophia museum , topkapi palace , underground cistern , hippodrome and archeological museum .
With a total seating capacity of about 40000 it is , except for the circus maximus and the hippodrome ( both racecourses ) , the largest structure for audience seating of the ancient world ( izenour , 1977 ) .