Yag (Oil) Mosque The Yag Mosque, also known as the Oil Mosque, is located in the old town of Adana, Turkey. Originally built as the St. Jacob Church in 1250, the Eastern Orthodox Church was constructed by the Byzantine Empress to serve Byzantine Christians on pilgrimage to the Holy Land. However, the church was built outside of the city walls due to hostility towards Eastern Orthodox Christians from the Armenians in the city. In 1380 AD, the Armenian Kingdom of Cilicia was taken over by Şihabeddin Ahmed, who converted the church into a mosque. The Yag Mosque is now the oldest mosque in Adana and forms part of the külliye, which also includes a madrasah. According to Evliya Çelebi, a famous Ottoman-era traveller, the mosque's location outside the city walls was due to historical tensions between the Armenians and Eastern Orthodox Christians. Despite this troubled past, the mosque stands today as an important example of the city's diverse cultural heritage. In 1359, the Mamluk Sultanate gained control of Adana, prompting Turkish families to migrate to the city and convert a church into a mosque in 1380. Ramazanoğlu Ahmed Bey was responsible for commissioning the conversion. The mosque underwent renovations in 1501 under the supervision of Gıyâseddîn Halil Bey. In 1525, Piri Mehmet Paşa constructed the minaret, and in 1558, the school building (madrasah) was built. The mosque was originally known as the "Old Mosque," but it was later renamed the "Oil Mosque" after an oil market was established in front of the monumental courtyard gate in the 19th century. The prayer room of the mosque is rectangular and features five naves with four rows of columns. The mihrab, indicating the direction of Mecca during Islamic worship, remains from the building's time as an Eastern Christian church. The mosque's gate, adorned with intricate calligraphy, is made of yellow and black stones. Located within the mosque's courtyard, the medress contains classrooms, cells (bedrooms), and a kitchen. The classrooms are topped with domes, while the cells feature cradle arches situated above arcades. Among the noteworthy features are the wooden archways outside each cell door, showcasing some of the finest examples of wooden artwork.