Since the 15th century the Quirinal Hill had been loved by refined humanists who used its small gardens for their literary banquets. Due to its central location in the city and its healthy fresh air, since the 16th century the Quirinal Hill was considered an ideal pleasure-palace location by many powerful cardinals, including Ippolito d’Este (the owner of Villa d’Este in Tivoli). Later it also became the summer seat of the Papacy. With its towers and high walls, the complex encloses one of the most highly praised gardens of that period, laid out in different areas, each with a different view of the city, with wooden structures forming galleries and domes lined with plants so that guests could take a stroll in the fresh shade. The formal gardens were laid out with blooming flowerbeds – with many valuable bulbous plants in the 17th century – and with a rich decor of ancient sculptures, of which only a part have survived. There was also a thicket with a large variety of trees and a rock fountain with a mosaic flooring and water features. The surrounding walls were covered with espaliers of citrus fruit and pomegranates. Each Pope left a sign of his personal taste, with the help of important architects and sculptors, creating a stratified complex which nonetheless remained based on the 16th-century structure, even though many fountains mentioned in the historical records are no longer in place. It was only at the end of the 19th century, with the arrival of the Savoy royal family, that the symmetries of the paths and flowerbeds were substituted by a more open and articulated layout, following the picturesque style that had become popular, even if belatedly, in Italy.