We are traveling from Positano to Pompei by car service, visiting the site for about 2-3 hours, then a car will take us to the Naples train station. We are staying at an apt. in Rome and need to arrange to get our keys, so I have to give an approximate time of arrival. Would a train at 14:40 from Naples give us enough time? I thought that 3 hours in mid June, with a 9 y.o. would be as much as he could absorb. We may a hire a guide for 2 hours to make more efficient and more interesting use of our time.