This is Constantine's Arch. I found the Black Portal in Trier, Germany more interesting because it is still in use.
The second group to tour the Forum arrived late and had to scramble and split into two groups to join later tours which didn't make those tour directors happy. Our guide just didn't have a good sense of timing when dealing with 34 people.
I got a bit out of sync and missed some of the morning things so I will start another blog. This one is starting to take long to upload because of all the photos in it.