The Pope is the leader of the Roman Catholic Church. So far there have been 265 of them (since the first century AD).
P.S.: we're not going to include all sites ever visited by a pope - just those that are strongly linked to one or all of them
World Heritage Sites connected to 'Popes':
Avignon From 1309 to 1377, the pope resided not in Rome but in Avignon (Palais des Papes)Pienza Was named after and redesigned by Pope Pius II (Pope between 19 August 1458 - 15 August 1464)Rome Rome with Holy See's exterritorial rightsVatican City The Holy See has been the residence of popes since early Christian times