Lake Iznik in Turkey has been holding onto some secrets for centuries. Thanks to some aerial photographs, archaeologists have realized that the Turkish lake holds the sunken ruins of an ancient church and perhaps even a pagan temple, Live Science reports.
Back in 2014, the local government of Bursa Province took some aerial survey shots of the lake in the town of ?znik in northern Turkey. Mustafa ?ahin, a professor of archaeology at Uluda? University in Turkey, came across the images and quickly realized that an unusual structure was lurking beneath clear waters: the ruins of a vast church. ?ahin and the Lake Iznik Excavation Archive have been rooting around the waters ever since, slowly but surely unraveling the story of this mysterious structure.
Over four years after it was first discovered, the site is now being turned into an underwater archaeological museum and hopes to earn a place on the UNESCO World Heritage List. More recent excavation work on the area is also hinting that the church, dated to when this part of Turkey was part of the Roman empire, might have been constructed on top of an ancient pagan temple.

The sunken ruins lay just 3 meters (10 feet) below the surface of the water and about 50 meters (160 feet) from the shore. Around the edge of the structure, there are many rough stones, which could provide some clues as to the story of the church’s demise.
“This shows that the structure collapsed. ?znik has gone through many earthquakes that destroyed such structures,” professor ?ahin told the Do?an News Agency in 2014. “The best known is the one that occurred in 740 CE. Our first observations show that the structure collapsed in this earthquake and that the coastal side was submerged. The church was subsequently not rebuilt.”
The church, or basilica, was built under the Romans sometime towards the end of the 4th century CE, when the town was called Nicaea. Over the ages, Nicaea has been home to numerous civilizations, including the Bithynian Empire, the Roman Empire, and the Ottoman Empire. As such, it’s also been graced with a huge amount of influence from both Islam and Christianity; the Eastern world and the Western world.
Nicaea is perhaps best known for the First Council of Nicaea in 325 CE (or for being prominently alluded to in Dan Brown's The Da Vinci Code). After Constantine became the first Christian leader of the Roman Empire, he organized a meeting of hundreds of bishops and religious leaders to attempt to formalize a centralized doctrine of Christianity. The decisions and ideas that sprung from the council helped to shape many of the core theological ideas that Christianity still holds.