<human>: Can you give me the gist of the text in a nutshell?

I will be traveling with my family to Rome and from there I will take a Royal Caribbean cruise for 7 nights to Genoa, Marseilles, Barcelona, Palma De Mallocro, and finally Valencia. At each stop I will be able to go on a couple of excursions or explore the city with my family by our selves. (*I will be there in late June/early July)

My question is if you have roughly 10-12 hours (mid-morning to night) what would you do?

I already plan on going on a short trip to visit Camp Nou in Barcelona (because I'm a huge soccer fan) (I will also have the most of the day to visit Barcelona after this) and I am strongly considering taking an trip to Monaco to see the Monte Carlo Casino (would you recommend this over Genoa?)

I have no idea what I should see in Marseilles, Valencia, Palma De Mallacro though!
<bot>: I have a day in Barcelona, Genoa (or Monaco), Palma De Mallacro, Valencia, and Marseilles what should I see??