Pope Leo visited the 17th-century Sultan Ahmed Mosque in Istanbul as part of his meeting with Muslims and Christian leaders.
This marked his first visit as leader of the Catholic Church to a Muslim place of worship during his four-day trip to Turkey.
After visiting the mosque, the Pope met privately with Turkey's Christian leaders at the Syriac Orthodox Church of Mor Ephrem.
Following proper etiquette, the pontiff took off his shoes and walked through the carpeted mosque wearing only his white socks.
As per multiple reports, the Vatican had planned for the Pope to have a short moment of silent prayer at the Blue Mosque, but the imam said the Pope decided not to participate.
The imam added that he told the pontiff, "'If you want, you can worship here,' I said. But he said, 'that's OK.'
"He wanted to see the mosque, wanted to feel (the) atmosphere of the mosque, I think. And was very pleased," the Imam added.
The Blue Mosque’s official name comes from Sultan Ahmed I, the Ottoman ruler from 1603 to 1617, who commissioned its construction.
The mosque is adorned with thousands of blue ceramic tiles, which is why it is popularly called the Blue Mosque.
