Touring ancient Rome

Our first full day in Rome, we hit the ground running once again. We were picked up at our hotel early for a tour of ancient Rome. We were in a group of about a dozen other English speaking folks. We threw coins into the Trevi Fountain, which, according to a Roman custom made famous in modern times, in part, by Audrey Hepburn's character in "Roman Holiday"  means we will return to Rome someday.
From the fountain we walked on through narrow streets past a spot in which some of the remaining pillars from Nero's golden  palace could be viewed.

Not much else is left of what the Emperor built in the areas which burned while he "fiddled."  His memory was cleared by his successors who built the Coloseum on the site of the lake and gardens where there once stood an enormous statue of Nero. If I understood our Italian guide correctly, these pillars we passed on the way to the Pantheon were salvaged for use only because of their economic and constructive value and not out of homage to the Emperor Nero.
The Pantheon is a wonder. It boggles the mind how such a thing could have been constructed without the modern methods or equipment we take for granted. That is survives in such amazing condition is also incredible. Built as a "temple to all the gods" of the pagan world, it is now a Christian church. The oculus remains open and our guide was careful to tell us "when it rains in Rome, it rains in the Pantheon." She pointed out the drainage holes in the center of the floor as proof.
The artist Raphael is buried in the Pantheon. He died very young, said our guide, because "he knew too many women."
I could have lingered there, marveling at the the rotunda, the dome, the carvings and frescos for long minutes we were not afforded. All too soon it was time to move on.
From the Pantheon we walked to Piazza Navona. The Fountain of the Rour Rivers in the middle of the square was something to behold. I did not know much about the artist Bernini until I realized how many magnificient works in Rome are attributed to him. In the short breaks we had, I read excerpts from our guide books about him with great fascination. His work on both the Fontana dei Quattro Fiumi and the Fontana Trevi were impressive and there was more to come...though later in that day and then the next.
The Piazza, home to one of the most famous of European Christmas markets during the holiday season each year,  is built upon the site of ancient arena. It is also the site where Saint'Agnes is said to have been burned at the stake for refusing to marry the nobleman her family had betrothed her to.
Again, I longed to stop a while and watch the artists painting portraits and landscapes there and to people watch for a bit but such was not to be.