Selahaddin Eyyubi Mosque or Saint Johannes Prodromos Addai Church The Selahaddin Eyyubi Mosque, also known as the Saint Johannes Prodromos Addai Church, is a grand historical building located in the heart of Sanliurfa. It is considered one of the largest structures of its kind in the city. The church was built in the 19th century, on the ruins of the Church of St. John the Baptist, which had been constructed by Bishop Nona back in 457 AD. As the largest church in the region, it was also referred to as a cathedral. The building had been abandoned for quite some time before it underwent renovations and was eventually reopened as a Muslim place of worship in 1993. The entrance to the mosque is situated in the west, and the main congregational area was constructed based on the narthex of the previous church. The building boasts large windows that allow ample natural light to enter, and still contains half-columns and embossed dragons that date back to the original structure. Given that Selahaddin Eyyubi had utilized the building as a mosque for a period of time, it was named after him.