Medina of Marrakesh Ben Youssef Madrasa; "This madrasa was one of the largest theological colleges in North Africa and may have housed as many as 900 students" (wiki)
Morelia Universidad Michoacana de San Nicolás de Hidalgo. It was founded in 1551 as the Colegio de San Nicolás by Vasco de Quiroga, first bishop of Michoacán. It is one of the oldest universities in America and one of the most important public universities of Mexico.
Oaxaca and Monte Alban Oaxaca: original building to house the Universidad Autónoma Benito Juárez (now only the law department)
Ouro Preto Mining School (1876, in historical center) of the Universidade Federal de Ouro Preto