During the modern times, 16th and 17th century, the Colosseum became of great interest for the Church. Pope Sixtus V wanted to turn the building into a wool factory. The idea was to provide employment for Rome's prostitutes.
His plan never became a reality, because of his premature death. Cardinal Altieri, decided in 1671, to transform it into a place for bullfights. The idea was finally abandoned because of public outcry.
A big change appeared in 1749, with Pope Benedict XIV’s idea. He said that the Colosseum is a sacred site, as it was a place where early Christians had been martyred. The view was popularized in 1653, by Fioravante Martinelli, who listed the Colosseum at the head of a list of places sacred to the martyrs. This theory appeared in his book - Roma ex ethnica sacra.
Later popes continued this tradition and developed many restoration projects, in 1807 and 1827, the exterior walls, and in 1831, 1846 and in the 1930s, the interior was. The Colosseum arena substructure was partly excavated in 1810–1814 and 1874 and was fully exposed under Mussolini in the 1930s.
In the 20th and 21st centuries, The Colosseum became a site for Roman Catholic ceremonies. Pope Benedict XVI performs the Stations of the Cross called the Scriptural Way of the Cross, on Good Fridays.