The Museum of Islamic Art in Cairo, Egypt has an impressive collection of coins from various Islamic empires, sultanates, dynasties, and caliphates. In particular they have a really fascinating collection of gold and silver coins from the Ottoman Empire and Mamluk Sultanate. Many of the Ottoman coins bear the tughra, a calligraphic monogram, signature, or seal used by the sultan. There are also Mamluk gold coins below which bear the names of Sultan Baybars and Sultan al-Mansur Qalawun.