Castel Gandolfo
By the 1930s, the smoke and sky-glow of the city had made it impossible to conduct useful observations in Rome. Pope Pius XI relocated the Observatory to Castel Gandolfo, which is southeast of Rome. By 1961, the same problems with light pollution made observing difficult at Castel Gandolfo. The Observatory then established the Vatican Observatory Research Group (VORG), with offices at the Steward Observatory of the University of Arizona in Tucson, Arizona.