Rome before the tour starts

I wouldn't miss the Borghese Gallery and a stroll--or bike ride--through the park. (You must reserve tickets for the gallery; it's small, so space is limited, but it is fabulous!) The Pantheon is amazing, and the square in front is a great place to relax and people watch. And you shouldn't miss seeing Trevi Fountain and throwing in a coin!

Ditto the Borghese it's fabulous and reserving online is easy (http://www.ticketeria.it/Default-eng.asp). The park is pretty to walk through and a nice respite from the city. Stroll up the Via Veneto on the way and stop at the Cappuccin Crypt - decorated with the bones of monks (really). Do not miss the Pantheon, it's also stunning (and free!). If you have Rick's guidebook, the nighttime walk that hits most of the major fountains (including Trevi). It was a highlight for me, especially seeing how many people on a week night were just out strolling. Grab a gelato at Gelateria San Crispino (Via della Panetteria, near the Trevi), grab a seat, watch your wallet, and people watch.

Don't miss the Borghese. Spend some time strolling around Piazza Navona, Campo dei' Fiori, Pantheon and the Spanish Steps. Tours keep you moving at a quick pace so use your time to relax and take in the city.

In addition to the Borghese, there are SEVERAL things I could suggest:

1. Consider one of the Catacombs tour

2. If you are a religious person, I found both Mamertine Prison and the Scala Santa INCREDIBLY moving. Scala Santa has virtually no tourists -- just you and the nuns. However, climbing the steps on your knees is VERY painful.

3. Take a night stroll (passagiata) with the Romans. End up in the Piazza Navona. Such a thrill.

4. Trevi Fountain by moonlight

5. The new baths exhibit

6. Pantheon

I know there is more -- but I'm just not thinking about it all.

If you are out strolling about and see a church (and you will!) go inside! I walked into every church I passed, can't even remember most of their names, and was continually blown away by their grandeur. One of the most impressive churches I saw in Rome was Sta Maria Maggiore, near Termini.

I continued this M.O. in every italian city I visited, the churches were fabulous everywhere I went. A few times I hit it in time for mass. In Venice I went to evening mass after the basicilica closed to the public, it was magical. I heard monks chanting in Florence. Once I was in a gorgeous church as two organists and a soloist were rehearsing! Another time the choir outnumbered the mass attendees.

The random churhes were the favorite part of my 3 week trip.

Also while in Rome, take a walk thru Trastevere, it's a very authentic neighborhood.

I would second some of the suggestions already
mentioned including Pantheon, Mamertine Prison
(next to Forum) and St. maria Maggiore near Termni.
I would also take a short trip outside town to the
San Sebastian Catacombs and Appian Way.

You could take a private tour and visit the places that you are not seeing on your other tour....There are over 400 churches in Rome....it is amazing. The catacombs are also very interesting to see. Marilee