The grand colonial high school next to the old university was founded by the Jesuits in 1687 and remains one of Argentina's most prestigious public secondary schools. The current main building, with its colonnaded courtyard and clock tower, dates from the early 20th century.
Visitors can enter the central patio during school hours and the historical museum on the upper floor by guided tour. The school still requires Latin in its curriculum — a tradition unbroken since the 17th century. Among its many famous alumni is Manuel Belgrano, designer of the Argentine flag.