The Maristan of al-Mu'ayyad or Bimaristan al-Mu'ayyadi is a bimaristan constructed by the Mamluk sultan al-Mu'ayyad Sheikh between 1418 and 1420. It is located on the southern edge of the Darb al-Ahmar district in Cairo, Egypt, near the Citadel of Cairo and the former Bab al-Wazir gate. It did not serve its function as hospital very long and stood ruined for many years. Its facade and main walls have survived, and have been recently restored.