Built in the city centre at the end of the 16th century by the Counter-Reformation Oratorian community founded by St Philip Neri, the Oratory of the Girolamini is a large monumental complex and an outstanding example of Baroque architecture. The church and the picture gallery contain many exquisite artistic treasures while the library boasts an extraordinary collection which has been open to the public since 1586. At the beginning of the 18th century, the philosopher Giambattista Vico, who used the library, encouraged it to acquire the library of Giuseppe Valletta, which became one of the most significant components of the library’s collections. With over 150,000 volumes of philosophy, history, theology, patristics, Church history, and literature, it is one of the largest library collections in the south of Italy.