This staircase is found at the Palazzo Barberini, which is now home to the Galleria Nazionale d'Arte Antica. The grounds were formerly a garden-vineyard which featured a palace built in 1549. The site was purchased by Maffeo Barberini in 1625, who eventually became Pope Urban VIII. Several architects worked on the palazzo over the course of its construction, including Carlo Maderno and his nephew Francesco Borromini, who took over after his death. This helicoidal staircase is one of its more famous features.