Colosseum Rating: Not Rated
Massive and impressive. Well worth seeing. There is a bathroom there, but the tour doesn't stop so you may want to skip the coffee on the way to Rome.
Sistine Chapel Rating: Not Rated
Small but impressive. If you like art you will be impressed by the detail. Plan on having your shoulders and knees covered to get in. No photography allowed and it's strictly guarded.
St. Peter's Basilica Rating: Not Rated
A MUST SEE. The most incredible building I have ever been inside of in my lifetime. No attention to detail was missed. The place took my breath away. I also saw The Pieta, my favorite sculpture in the entire world. I could have spent the entire day in this building. Flash photography IS allowed. Awesome, it will amaze you.
Vatican Museums Rating: Not Rated
Too much to see but well worth seeing what you can while you are there. Again, the attention to detail is really incredible. The amount of art is overwhelming. They have a nice gift shop. They sell "The Peace Cross" and special Rosaries. The Peace Cross makes a very nice gift and you can only buy them at the Vatican.