I will be going from Naples to Sorrento by train and I would like to stop at Pompei on the way.
Would it be possible to do this with a backpack or will I have to carry it around with me?
From memory there isn't anywhere to leave it, and, given that part of the world, even if there was I probably wouldn't recommend it. We did Pompei as a (long) day trip from Amalfi. Ferry and bus to Pompei,then train to Sorrento and finally a bus back to Amalfi ... Yes, with children in tow too! almost 9 years ago