Lyon- things to do

There is enough for three days, but I think that I would aim for at least 4 full days i.e. 5 nights for Napoli + Amalfi coast, which, if you have 8 nights total, means 3 nights / 2 full days in Lyon.

I think so, yes. It all depends on your interests. Rick has some suggestions here: https://www.ricksteves.com/europe/france/lyon. Click on At a Glance.

But you also need to consider how much time you'll need for what you want to do while you're in the Naples area. You mentioned the Amalfi Coast. Are you also interested in Pompeii? Herculaneum? Capri or one of the other islands?

It will take considerable time to get from Lyon to Naples or wherever you're staying in Italy and get settled in your new lodgings. If you have a total of 7 days, you won't really have 3 + 4 or 4 + 3 days by the time you subtract the many hours lost in transit.

We are actually staying in Conca di Marini for a month with many trips planned to Ercolano, Vesuvius, mozzarella farm, wine tasting, cooking class. Boat trips, Capri, Ischia, Pompeii, Pasteum, every little town from Sorrento to Salerno. I am pretty sure we will get back to Napoli and want to just see a few things while we are there. More time in Lyon if we need it.
We will be coming off a River cruise and have a 7 day gap to fill.

I've lived in, and in the vicinity of, Lyon for nearly 8 years and I'm still finding plenty to see and do there.

So, in response to this question:

Is there enough to do in Lyon for 3 days?

I have to chuckle in response.

Because that's kind of like asking if there is enough to do in Seattle for 3 days, if Seattle:

• Had been around for about four or five millennia longer than it actually has
• Was once the capitol of a nation organized by Roman conquest and was the birthplace of two Roman emperors
• Was a center of resistance activity during the worst conflict the world has ever known
• Was where an amazing machine that could be controlled by punch cards was invented to weave complex patterns into cloth, foreshadowing the Hollerith cards that were used more than two centuries later to control computers
• Was where modern motion pictures were invented
• Was chock full of grand open spaces, statues and monuments, beautiful beaux-arts architecture, winding, medieval streets, 500- to 1,000-year old churches, terrific museums, and shopping opportunities, both for new fashions and antiquities
• And, if it was widely regarded as the gastronomic capitol of a nation known globally for its gastronomy