The maristan was built by Sultan al-Mu'ayyad between 1418 and 1420; it was the second public hospital built in Cairo after that of Qalawun (1284). It is noted for its monumental scale, unprecedented in a civic building, which was clearly inspired by the nearby free-standing grandiose Madrasa of Sultan Hasan, and also for its portal, which is set in a pishtaq, a feature which gives the facade a Persian character. The portal has a muqarnas hood and a window with a pair of colonnettes with a snake, a symbol of healing.
The maristan is built on the site of the madrasa of Sultan al-Ashraf Sha'ban, which was founded in 1375/776 AH and demolished by Sultan Farag ibn Barquq in 1411/813 AH. The building is a shell and has lost many sections of its outlying structure. The area in front was leveled ca. 2005 by the Supreme Council of Antiquities to allow a full view of the maristan's facade.
Sources:
Behrens-Abouseif, Doris. Islamic Architecture in Cairo. Leiden: E. J. Brill, 1989.
Jarrar, Sabri, András Riedlmayer, and Jeffrey B. Spurr. Resources for the Study of Islamic Architecture. Cambridge, MA: Aga Khan Program for Islamic Architecture, 1994.
Meinecke, Michael. Die Mamlukische Architektur in Ägypten und Syrien (648/1250 bis 923/1517). Glückstadt: Verlag J. J. Augustin, 1992.
Warner, Nicholas. The monuments of historic Cairo: a map and descriptive catalogue, 137. Cairo: American University in Cairo Press, 2005.