Pompeii

The fastest trains from Rome to Naples are 70 minutes, and the train from Naples to Pompeii (Circumvesuviana) is about 40 minutes. So, you can certainly do it as a true day trip. Be aware that the Rome to Naples train will be much more expensive bought on the day of travel, and much cheaper if you buy in advance and can accept non-exchangeable and non-refundable tickets. Even if you are planning to buy on the day of travel, check the schedule, so you don't miss the last one home from Naples to Rome. The Circumvesuviana is a commuter line and tickets cannot be bought in advance (and are cheap in any case).

You can do it as a day trip. Can make for a very long day as Harold pointed out. And it is easy to spend four hours or more at Pompeii. Also, Pompeii has absolutely no shade and can be very hot in the summer so plan accordingly.

We did it as a day trip and it was a very LONG day. We left Rome fairly early in the morning and didn't get back until around 11PM. We wanted to do the site justice though and chose to see it this way. It was well worth it! We were able to spend most of the day in Pompeii. Even if you spend the entire day there though, you won't be able to see everything - it covers a very large area which was a surprise to us. That's part of the reason we got back so late - we didn't want to leave! Do your homework before you go and identify the things you want to see. Then anything you see after that is icing on the cake! Good luck and enjoy...

We visited Pompeii from Rome several years ago and had no problem making it a day trip. We spent the day there exploring and were back home by evening. Even in Oct. when we visited it was pretty warm so do keep that in mind. It was a fun day though! Buon Viagiio!

Thanks to everyone who responded. Very helpful!

Several years ago we used a company called enjoyrome.com for a no-frills roundtrip excursion to Pompeii and it was a long day. We boarded the pullman coach at 7:15 in the morning and returned to Roma around 5:00 in the afternoon. It was worth it to us because we did not need to make any connections and were able to spend four hours on-site. Pompeii is immense with few tourist amenities other than a visitor's center. Additionally, it is HOT, HOT in the summer, so carry water. In 2011 we went to Ostia Antica, which is the ancient Roman seaport located a short distance from Roma. It has everything Pompeii contains except the history. However, during the summer it possesses two amenities conspicuously absent from Pompeii: 1. shade and 2. a breeze blowing in from the sea. Buon viaggio,

In my opinion, I would suggest that you stay a night in Pompeii. Visit the ruins, the archeological museum in Naples and Hereculaneum. That would give you a great overview of the area. You've gone all that way, you might as well make the most of it. There is so much to see. A wonderful place to stay in Pompeii is Easy Bed Hostel. We just spent three nights there. We also hired a private guide and driver to take us around the ruins and into Naples and it was money well spent.

The downside of staying overnight is that J.S. would have to vacate his room in Rome and either schlep all his luggage with him back and forth or leave some of it in storage and return to pick it up.

Ditto Michelle's recommendation on Herculaneum. A great site, well preserved, better than Pompeii in some respects. See it if you can.

I appreciate everyone's comments. Thank you.