Introduction to the Basilica of Saint John in Laterano: The Basilica of Saint John in Laterano (Basilica di San Giovanni in Laterano) is the full name of the Cathedral of Saint John the Holy Savior and Saint John the Baptist in Laterano. , is the Catholic Archdiocese of Rome and one of the four grand basilicas in Rome. It enjoys the title of the mother church of the Catholic Church in the world. (ticket 2 euros)