The Church of St Simeon the Tanner, is carved into a cave on a ridge of Muqattam Hill. Thought to be the biggest church in the Middle East, it seats 17,000 worshippers. But this church is not old, it was built in the 1970s, in a cave thought to have once been home to early Christian hermits, and named after St Simeon, the 10th-century ascetic who prayed to make Muqattam move at the behest of Fatimid caliph Al Muizz Li Din Allah.
Today the church is a major site of Coptic pilgrimage, and there are several other churches scattered around the ridge area. Fridays and Sundays, when mass is held, are chaotically busy at the church. For a more relaxed visiting experience, avoid these days.