Sitting across from the Hagia Sophia, the majestic Blue Mosque dating from 1616 is one of the best historical places in Istanbul. Foreigners can glimpse into the life of secular Muslims in Turkey because the mosque still operates daily for prayers. Also called Sultanahmet cami, entrance to see the blue stained glass windows of the interior is free or donations are gratefully accepted. With its 260 windows and unique 6 minarets, the Blue Mosque is the most famous in Turkey.