Rome, the Eternal City, and is home to the coliseum, the Pantheon, Trevi Fountain, and so much more. Vatican City has so much to offer visitors with St. Peter’s Basilica and Square and the beautiful Sistine Chapel. A wonderful honeymoon location.
Venice offers the mysterious canals and the awesome St. Mark’s Square. You may wish to travel towards Florence and Pisa, and the rolling hills of Tuscany afford magnificent views. One can explore The Amalfi Coast with the cities of Pompeii and Sorrento then take a ferry to Capri (one of my favorite places).
Other areas not quite so well known include Cinquie Terra and southern Italy. All areas of Italy present some wonderful travel options.