The grandiose Quirinal Palace, situated on top of the eponymous hill, has an extremely important historic-artistic place among the vast architectonic heritage of Rome. Built by Pope Gregory VIII in 1574 as a summer palace and designed by architect Ottaviano Mascarino as the enlargement of a previous fifteenth-century villa, formerly the property of Cardinal Oliviero Carafa and later the home of Ippolito d'Este, the palace was enlarged and embellished during the pontificate of Sixtus V by a succession of noted architects, such as Domenico Fontana, who created a large courtyard by building a long wing and an adjacent edifice; decisive changes were then made by the architects Flaminio Ponzio, and Carlo Maderno who built the splendid Paolina Chapel for Paul V in the seventeenth century, which is still used today on occasion of solemn religious ceremonies, the Sala Regia and the papal apartments; Gian Lorenzo Bernini who in 1638 placed the Loggia of the Benedictions over the majestic portal; Alessandro Specchi and Ferdinando Fuga who designed the elegant papal stables, nowadays used for exhibitions. The papal residence until 1870, then, with the annexation of Rome to the Kingdom of Italy, palace of the royal family, the splendid Quirinal Palace has housed the president of the Republic since 1947. Among the many masterpieces hanging in the spacious lavish chambers, sumptuously furnished with antiques, are the outstanding frieze and fresco created in 1616 by Giovanni Lanfranco and Agostino Tassi, adorning the Hall of the Corazzieri, previously the Sala Regia, the pictorial cycle in the Gallery of Alexander VII Chigi to a design by Pietro da Cortona; the famous painting by Pietro da Cortona depicting the Departure and Triumph of David, in the Sala del Balcone; a painting depicting St. John the Baptist, in the sitting room of the same name, attributed to Giulio Romano and, further rich pictorial decoration, outstandingly the splendid Annunciation above the altar, painted for the Chapel of Our Lady of the Annunciation by Guido Reni in 1609; in addition, there are the precious collections of statues, tapestries, clocks, porcelain and old carriages. The palace is surrounded by 4 hectares of luxuriant "Gardens", a network of splendid avenues laid out by various pontiffs from the seventeenth century onwards, starting with Clement VIII Aldobrandini, who created the lovely Organ Fountain, with its admirable jets of water accompanied by music from a hydraulic organ, standing in the depths of a niche superbly decorated by stucco work and mosaics.