The most famous site in Coptic Cairo is the Church of the Virgin Mary, better known by its nickname, the Hanging Church. This name comes from the fact that it was built atop the walls of the 4th century BC Roman fortress of Babylon, the remains of which are still visible about Coptic Cairo. Although the effect is significantly diminished today by the fact that the ground level has risen over 30 feet over the centuries due to the accumulation of trash and dust, but originally this church towered above its surroundings on the high walls of the fortress.
The church dates from the 9th century, but the site is thought to have first been occupied by the church as early as the 3rd century AD, making it one oldest Christian religious site in Egypt. It is also considered to be the most beautiful of the old churches in the area, although a 19th century portico built onto the front of the church obscures some of this beauty. Inside the portico though the 13th century facade of the church is still visible. The ornate interior is covered in bone and ivory inlaid designs that seem influenced by the geometric and organic forms that characterize Islamic art.