The Collège des Quatre-Nations, founded by Mazarin and built according to plans by Le Vau, became the headquarters of the Institut de France in 1805. The institute comprises five academies, including the Académie Française. Some admit their new members beneath the famous dome of the old chapel. Two wings forming a quadrant link the chapel to the square pavilions, creating a balanced and harmonious Classical ensemble. The splendid Bibliothèque Mazarine is the oldest public library in France.