Rome: Things I Didn't See, But Should Have

I didn't see a lot of things in Rome.  There is lots of stuff to see and I only had a few (very hot) hours to see stuff.  Before I went to Rome, I made a map of all of the things that would be fun to see, just in case I got an opportunity,although I knew I wouldn't get to see most of it.  (You can see the interactive map here, if you would like.)  Even that wildly ambitious list left out a lot of sites.  You can see the little blue points below are all of the things that seemed like you out to see.  All of the little red dots are all of the other museum and historical sites that you could visit around the city.

The map below shows the things that I actually saw.  (You can see the interactive version of the map here.) I am not sure that this is the map of a really good tourist.

So, there are lots of things that I missed.  Some because I wasn't in a site-seeing mood, and some that were just not feasible to get to, given my time constraints.  But I thought, since I had done the research for this already, that I might share some of these places with you in any case.  I will add some more info later about different places that I would have seen if I had had the time and inclination--such as the Spanish Steps, the Trevi Fountain, etc.