Is the Siena City Wall a worthwhile sight to see? Also, I will be arriving at Piazza Gramsci and visiting Il Campo, so is it possible to see a portion of the wall near either of those locations?
Not from the Campo, but walk from Piazza Gramsci towards the Fortezza, and there are quite a lot of the original defences intact.
Alternaively, most of the old gates at Porta Camollia, Porta Ovale or Porta Pispina are intact.
TimW: Thank you for this information! From Piazza Gramsci, is it within walking distance? And how would I take public transportation to one of the gates?
Nine minute walk from Piazza Gramsci along via Camollia to the Porta Camollia --- it's a nice, interesting, lively, untouristy street that I've walked along many times.
Thank you nancys8!
If you are arriving on the bus from Florence, you will see Porta Camollia and the Fortezza on your journey into the city. The Fortezza is just a couple minute walk the Piazza and has a nice view of Siena and the countryside.
Thank you charylm!