Complex sentence: Adjacent to the Basilica di San Giovanni in Laterano, the cathedral church of Rome, Italy, the Lateran Palace is now occupied by the Museo Storico Vaticano which illustrates the history of the Papal State.
Split into simpler sentences: Adjacent to the Basilica di San Giovanni in Laterano, the cathedral church of Rome, Italy. The Lateran Palace is now occupied by the Museo Storico Vaticano which illustrates the history of the Papal State.