BURSA, Türkiye

Archaeologists in northwestern Türkiye are preparing an ancient basilica submerged in Lake Iznik for a visit by Pope Leo XIV, expected later this year to mark the 1,700th anniversary of the First Council of Nicaea — one of early Christianity’s most important gatherings.

The basilica, located about 20 meters off the lake’s shore in the province of Bursa, is believed to stand on the site of the First Council, which convened in 325 A.D. with bishops from across the Christian world to settle key theological disputes.

The site was discovered 11 years ago at a depth of up to two meters.

Underwater excavations, authorized by the Turkish Ministry of Culture and Tourism, have been underway since 2015 under the supervision of Mustafa Sahin of Bursa Uludag University, with support from the Bursa Metropolitan Municipality.

In an interview, Sahin told Anadolu that a team of 60 archaeologists, anthropologists, restorers and art historians is working to ready the site for the Pope’s planned visit between Nov. 28 and 30.

“All our efforts until then will focus on landscaping and exhibition arrangements,” Sahin said. “Our preparations are entirely aimed at presentation.”

Measuring 20 by 40 meters, the basilica is considered Iznik’s largest known church. Sahin said evidence suggests the structure is the long-lost Church of the Holy Fathers, long referenced in Christian sources but never confirmed until now — a claim increasingly accepted among scholars.

He said Pope Leo’s visit could help make Iznik (historically known as Nicaea) an important center for Christian pilgrimage and faith tourism.

“Even a single stone here holds great meaning for Christians,” he said. “There’s no need for grand buildings — the existence of this site alone is significant.”

Sahin added that the basilica was first built as a chapel dedicated to Saint Neophytos, destroyed in an earthquake in 358 and rebuilt after 380 A.D. Excavations have uncovered 37 graves, many restored and reburied in their original locations to preserve authenticity.

“We’ve restored the graves to their original state so they can be safely displayed,” he said.

Pope Leo XIV’s planned trip to Iznik will be his first visit abroad since assuming the papacy, after which he is expected to travel to Lebanon, according to Vatican News.