Two days in Naples after the South Italy tour: suggestions?

We are taking a BOSI tour too and booked a couple of extra days at the end. We're taking the ferry to Ischia. Check it out.

You could always revisit an area that you liked in the guided your.
Or head to Capri or Ischia if that's not already on the tour?

Regarding Herculaneum, it is fascinating but also relatively compact, so 1/2 day is enough. You can probably squeeze in Vesuvius, although I have no idea how to get there from Herculaneum.

We planned an extra day in Naples after our tour since we wanted to see a performance at the Teatro di San Carlo. During the day, we enjoyed Napoli Sotterranea (Naples Underground), Piazza San Gaetano 68 Napoli, info@napolisotterranea.org. Going to Herculaneum is a good idea, I'd have liked to see that as well as Pompeii. The South Italy tour is great, you'll have a wonderful time.

atjsfo, I'm sending you a private message.

Same to Jim. I'm looking for tourmates!

Does your tour take you for a walk along the beautiful seaside Lungomare? Our hotel was very near it and we enjoyed walks there several times with it’s sweeping views of Vesuvius and the Castello dell’ Ovo. I would spend the whole day in Naples.

We added an extra day as well. Other have made great suggestions, so I would just add that the tour visits Santa Chiara, but not the attached convent with cloisters. We visited that and loved it. Additionally, a group that had added extra time all went to an evening concert at Gesu Nuovo ( opposite Santa Chiara). It was a donation and we didn’t need to buy tickets ahead. It was kind of a fun way to wind down what was a fabulous tour.

Thanks for any/all suggestions you give the OP as we are also on the SOI tour with 1 extra day in Naples.

Sister-in-law and I rented a car at the end of tour and drove to Calabria for an overnight to visit the tiny village her grandparents were from. It’s probably not something everyone would want to do without a reason, 4+ hours driving each way. But area was beautifully rustic and welcoming . It was one of the highlights of our trip.

I will second Patty’s suggestion to visit the cloisters at Santa Chiara. The Majorca tiles are beautiful.

This is a great tour. We didn't do it but a couple on our tour was going to Ischia for a few nights and I was envious. That would be my choice. I'm glad we went to Naples but we didn't need any more time there.

I'm booked on this tour for May 14th, can't wait. Hoping that it's clear soon about the 6 month rule for vaccines to enter Italy, I think it just got amended so that if you've had a booster is does not have an expiration as authorization for a 4th shot hasn't been authorized yet. Fingers crossed! Anyone else here going on this date? I'm arriving early a few days early in Rome and leaving Naples on the last tour day to visit my family in England before heading back to California.
On other tours prior to Covid I've arranged local walking tours, have you checked to see if there are any on offer in Naples, I've always found them to be really great as they take you off the beaten path usually and many times are free, just tips.

We had an extra day in Naples in 2015 and took the train west to the city of Pozzuoli. There we visited the "The Flavian Amphitheater, the third-largest Roman amphitheater in Italy. Only the Roman Colosseum and the Amphitheatre of Capua are larger. It was likely built by the same architects who previously constructed the Roman Colosseum." It is very grand and was utterly uncrowded at that time. You would need a little research about times and days of the week in these unusual times.

The Royal Palace in Naples is very nice. And the tour of the Opera House is very good. These two sites are around the corner from each other.
Several of the churches are spectacular and have multiple layers of history--San Gennaro, San Lorenzo, Santa Maria Antica.