History of Rome Library was officially founded on 15 June 1475. He restored several churches, including Santa Maria del Popolo, the Aqua Virgo and the Hospital of the Holy Spirit; paved several streets and also built a famous bridge over the Tiber river, which still bears his name. His main building project was the Sistine Chapel in the Vatican Palace. Its decoration called on some of the most renowned artists of the age, including Mino da Fiesole, Sandro Botticelli, Domenico Ghirlandaio, Pietro Perugino, Luca Signorelli and Pinturicchio, and in the 16th century Michelangelo decorated the ceiling with his famous masterpiece, contributing to what
Restoration of the Sistine Chapel frescoes have been predicted by previous restorers. One of the major dangers to the frescoes is automotive exhaust, and they are also vulnerable to the effects of the crowds of tourists that pass through the chapel every day, bringing with them heat, humidity, dust and bacteria (the latter of which can biodegrade paints and pigments). The clean plaster surfaces are more in danger from these destructive elements than they were when they were covered with a layer of smoky wax. Previously, the Sistine Chapel's only ventilation was from its windows in the upper level of the walls. To prevent exhaust fumes