A 13th century mosque that fell into disrepair after being used over the years as a soap factory, a slaughterhouse and a fort reopened in Cairo on Monday after undergoing a long restoration. The mosque of Al-Zhahir Baybars, built under Mamluk rule in 1268, spans an area of three acres just north of central Cairo, making it Egypt's third-largest mosque. The mosque underwent mechanical and chemical restoration to bring it back to its original condition, said Tarek Mohamed El-Behairy, who supervised the restoration.