Saint Mercurius Church (Coptic: ⲙⲁⲣⲕⲟⲩⲣⲓⲟⲥ ⲧⲁⲧⲣⲁⲡⲩⲗⲱⲛ ⲙ̀ⲫⲓⲟⲙ)[1] in Coptic Cairo is a Coptic Orthodox church situated just to the north of the Babylon Fortress in Old Cairo among a group of important churches, and within the area known as the Abu Sayfayn Cloister is to be found three churches and a convent. One of these churches, dedicated to Saint Mercurius, and is the largest in the district of ancient Babylon.[2]