What is "al-matariyyah"

Al-Matariyyah, Mataria, or El Matariya is a district in the northern region of Greater Cairo, east of the Nile, in Egypt. The district is unrelated to the El Matareya coastal town in the Dakahlia Governorate. The Al-Matariyyah district's location was part of the ancient city of Heliopolis, one of the oldest cities of ancient Egypt.