A Polish team of archaeologists may have found Egypt’s oldest church in a recent dig near the city of Alexandria.

The experts discovered the ruins of the 4th-century church while working at a Christian basilica site, near the ancient port Marea, reported The First News. Archaeologists were unearthing a 5th- to 8th-century church when they found the older church underneath the site. The basilica had been destroyed by an earthquake.

Dr. Krzysztof Babraj from Kraków’s Museum of Archaeology led the team, which has been working on preserving the basilica since 2000. “At the end of the last research season, under the floor of the basilica, we encountered a wall’s remains, which turned out to be the outer walls of an even older church,” explained Babraj. “This is one of the oldest Christian temples discovered in Egypt so far.”

The experts determined the age of the older church based on the form of its limestone walls. They also found ceramic and glass fragments. Both indicated that the church was from the 4th century.

The church’s walls were built in the shape of a cross, typical of churches in that day, reported Ancient Origins.

The discovery was important because experts don’t know of any remnants of churches from Alexandria. “Now we know how they could look,” Babraj explained, “which is why it is so important to continue our research that we have just begun in the old church.”

Nancy Flory is an Associate Editor at The Stream. You can follow her @NancyFlory3, and follow The Stream @Streamdotorg.