Native name: Yeralti Camii
Yeralti Mosque (known as the Ground Mosque) was the crypt of a former
Byzantine
fortress that was controlling the entrance of the Golden Horn , enemy ships were blocked from entering the Golden Horn by an anchored chain . The place was used by the Ottomans after the conquest of Constantinople as an ammunition store . Then in the period of Mahmut I (1730-54) the place was transformed into a mosque in 1757 . The low-ceiling is supported by squat pillars . There are 54 symmetrical buttresses in the main area and they are arranged in six rows of nine , which create little compartments for private prayer . In a side area , there are the tombs of two Arab soldiers killed in the first Arab siege . The mosque has a limited view because of its low ceiling .
)
