The Grand (Ulu) Mosque & Jesus Well The oldest mosque in the city center of Urfa province is the Grand (Ulu) Mosque, which originally served as a synagogue before becoming the Church of St. Stephen under Bishop Rabula's jurisdiction between A.D. 435 and 436. Nurettin Zengi later converted it into a mosque in 1170-1175, and it has been used for this purpose ever since. The mosque is part of the Anatolian multi-pedestal mosque group and has a rectangular construction plan with parallel three rows of diagonal vaults on one side to show the direction of Mecca. The last congregation location, which opens onto a fourteen-pointed arched courtyard, was initially used at the Şanlıurfa Ulu Mosque. Today, an octagonal bell tower serves as the mosque's minaret. Legend has it that the handkerchief sent by Jesus to King Abgar with his Apostle Thomas was left in a well inside the mosque. People believe that the water from the well has healing properties. King Abgar and his Kingdom of Edessa were the first to accept Christianity, and they sent messengers to Jesus to invite him to their country. According to the legend, Jesus could not come, but he sent his handkerchief with Apostle Thomas. When the king opened the handkerchief, he saw Jesus's face in the napkin and threw it into the well, believing that his face should bring health to everyone. It is believed that this well, which is now inside the mosque but was previously part of the church, is where the handkerchief was thrown. During the Republic period, the minaret was converted into a clock tower with the addition of an analog clock. It is now Urfa's only clock tower. The northwestern part of the mosque courtyard, surrounded by thick walls that belonged to the church before it was converted into a mosque, is now a cemetery.