Friday prayers are being held at the Hagia Sophia mosque in Istanbul for the first time since it was turned into a museum 85 years ago.
Only about 1,000 people are being allowed inside at any one time because of the coronavirus.
Turkish President Recep Tayyip Erdogan was among the worshippers.
A large screen and speakers were set up outside to broadcast proceedings to the large crowds gathered outside. The Governor of Instanbul ordered the mosque remain open until Saturday to allow worshippers to complete their prayers.