The church of St. Barbara is one of the oldest and the most remarkable churches in Cairo. It is situated on the eastern part of the Babylon fort and dates back to the 5th Century, though it was rebuilt around the 11th Century. It was named after St. Barbara, who was born in the beginning of the 3rd Century in Nicomedia in Asia Minor. She converted to Christianity and refused to marry any of the aristocratic young men in Alexandria, devoting herself to serving God. Her father was a Pagan, who continually tortured her, and then he complained about her to the Roman governor Marcianus, who in turn severely tortured her, but she resisted and refused to leave Christianity. Finally she was killed, together with her companion Juliana.

The Church takes a shape of a Roman Basilica, comprising of an entrance, a narthex, a nave, 2 aisles and 3 Sanctuaries that are located in the east wing of the church, the middle Sanctuary is the main one, dedicated to St. Barbara. After entering, from the narthex, there are 5 marble columns, with palm leaf capitals, which separate the nave from the 2 aisles. In front of the middle Sanctuary there is a semi-circular choir, which consists of 7 steps.

From the southern Sanctuary, of the church, visitors can enter through a doorway to a rectangular hall, which contains a chapel dedicated to St. Barbara, and is one of the very recent modifications to the church. From the northern Sanctuary there is a doorway that leads to the small church, which was consecrated to St. Cyrus and St. John.

This small church has 3 Sanctuaries. The middle one dedicated to St. Cyrus and John, the right one dedicated to St. George while the third one is used today for baptisms.

The most precious item, found inside this church, is a sycamore door that dates back to the 5th Century. The church has many icons, the most remarkable dates back to about the 13th Century. The main icons depict Christ surrounded by Angels.

There are other icons on the southern aisle of the church, representing the Virgin Mary and Jesus when he was a child, Jesus entering Jerusalem and the baptism of Christ.