The Early Christian Basilica of Agia Sophia is located south of Panormo and was one of the largest basilica found in Crete with a length of 54m and a width of 23m.
The basilica was excavated in 1948 by K. Kalokyris and N. Platon, and was built in the 5th-6th century, like most seaside basilicas of that era. It was violently destroyed by Arab invasion in the 7th century, but continued to be used till the 9th century.
It was a three-aisled basilica with a transept with a shape of archaic cross (†). The large dimensions of the church testify that Panormo was a very powerful city. Maybe it was the seat of the Diocese of Avlopotamos, although it is likely to have been the Diocese of Eleftherna, which was moved here after the destruction of the city.