We happened to walk here when we saw the long lines at the Vatican. We purchased the audio guide, which is well worth the price. The photos we took from here are some of the best we took on our trip. I don't think anybody would be diappointed by spending a few hours here.

The bar/coffee shop at the top has wonderful views over rome and you don't have to queue unlike the dome of St. Peter's. there is also one table with a perfect view of St Peter's and the piazza.

The Castel Sant' Angelo is just a few minutes away from the Vatican. This is worth walking through and looking around. I've never been in an old castle, I'm so glad I didn't miss this experience. The view is amazing from the top!

This site has really an incredible view of Rome from the top. The inside is also incredible when you know what you're looking at! These places have so much history to them that it would be impossible to put a sign up everywhere to explain the history of each place! So go and enjoy with assistance from a guide or book!