The Collegium Trilingue, founded in 1517 under the patronage of humanist Hieronymus van Busleyden, was one of the most important institutions of the Northern Renaissance. The college was created specifically to teach the three ancient languages — Latin, Greek, and Hebrew — at a time when such learning was considered radical. Erasmus was instrumental in its foundation, and the college attracted scholars from across Europe during its first decades.
The building on Busleydenstraat is a handsome 16th-century structure that has been restored and returned to use as part of KU Leuven. It's not fully open to the public, but the courtyard is usually accessible and worth a look. The restored interior, which includes an original lecture room, can sometimes be visited through guided tours of the university's historic buildings. Even from the outside, the building is a reminder of Leuven's central role in European intellectual life at the moment when the Renaissance was reshaping the continent.