began to decline, however. After a period under the administration of the castle of Lariano, it passed to the Genzano district, which at that time registered only 100 residents. Around 1400 all the territory became the property of the Monastery of Sant'Anastasio alle Tre Fontane and, after a brief period under the Savelli once more, was sold to the Abbey of Grottaferrata. Pope Sixtus IV handed Ariccia over to the Savelli, who executed several works to improve its condition, including the draining of the volcanic lake (Lake of Vallericcia) which lay to the west, between the hills and the sea. Systematic archaeological excavations of the site began around this period. In 1637 Giovanni Argoli, at the request of his patron the Cardinal Lelio Biscia, writes up a description of votive objects and inscriptions found during excavations at Aricia. In 1661 the city passed to the powerful Chigi family, who rebuilt the splendid Palazzo Savelli Chigi in the main square, in which the invaluable Chigi archives were housed. The Chigi Pope Alexander VII lived for long periods in Ariccia and drastically changed its character, with important contributions from the prominent Baroque sculptor and architect Gian Lorenzo Bernini, designer of the piazza of St Peter's Basilica in Rome. Among Bernini's rich contributions to the character of the town were the piazza and the Collegiata di Santa Maria Assunta which faces the palazzo. In 1854 Pope Pius IX ordered the construction of a bridge. This bridge bypassed the large wood (now the Parco Chigi) in the valley, which hindered access to Ariccia from Rome along the Via Appia. Nearly a century later, the bridge—along with much of the city—was destroyed by retreating German troops during World War II. Rebuilt in 1947, it crumbled suddenly in 1967 and was rebuilt again. In 2015, the Roman Curia's yearly Lenten spiritual exercises were again held at Ariccia, at the Casa Divin Maestro (House of the Divine Master), from 16:00 on the First Sunday of Lent, February 22, 2015, to the morning of Friday, February 27, 2015. The 2015 exercises were to be led by Carmelite Father Bruno Secondin, on the theme from the readings of the Prophet Elijah, "Servants and prophets of the living God"; during the retreat, all audiences are suspended. Main sights The most noteworthy sight in Ariccia is the northern entrance from the famous bridge which leads to Bernini's Baroque square. The main