Take a look at our 1-week plans for Rome and Venice? Offer suggestions?

For your Vatican City day, strongly consider splurging for one of the early entry tours, that get you into the Sistine Chapel ahead of the herds. These are offered by Walks of Italy (The Pristine Sistine), Dark Rome, and the Vatican itself, among others. You start at 7:30 AM or so, but you get to actually see the Sistine Chapel without feeling you are in Times Square. If I go back, it's the only way I'll do it.

For the Colosseum, you can get tours from them directly - no need to use a third party, unless the one you want is sold out.

As for Venice, of course you'll see St. Mark's Square, but find some time to get as far away from it as possible, to see other sides of Venice. Look at a map of Venice, and find St. Mark's Square, the Rialto, the train station, and the most direct foot paths between them. Now, go anywhere else in town, and voila! - most of the tourists will disappear.

You seem to be apologizing for your trip plan, but it looks good to me!

Bit of a splurge, but a private guide will make the Colosseo/Palatino/Foro Romano area come alive. 4 hours for 3 people for not much more than a small group tour with Walks of Italy. Contact SoniaTavoletta63@gmail.com.

We used Walks of Italy and were very happy.
https://www.walksofitaly.com
The Pristine Sistine tour was worth every penny. Going back thru the Sistine after our Vatican Museum bit was actually frightening, the crowds were shoulder to shoulder in there.
We had a fantastic guide for the Coloseum thru Walks of Italy. He was a retired civil engineer, as the daughter of a civil engineer I loved that he focused more on the structure/engineering rather than the "lore"
We also did the Catacombs and Crypts tour. Enjoyed that very much as well, although those 3 sites can easily be done without a guide. Your son might find the Capuchin Crypts very interesting!

Our other favorite spot was Borghese Gallery- simply amazing, you'll need a timed entry ticket which is nice because it limits the crowds inside.

Venice- get to St Mark's Basilica right when it opens- you can book an entry there for a few euros. The line to get in was already blocks long, we got in ahead of all the crowds and were very happy about that.
We did the Secret Itineraries tour of Doge's Palace and really liked that.
http://palazzoducale.visitmuve.it/en/pianifica-la-tua-visita/special-itineraries/secret-itineraries-tour/

Once you have seen the Basilica and perhaps do the Secret Itineraries- head away from San Marco and explore the quieter parts of Venice. We can't wait to go back.

Your itinerary looks very doable. We were in Rome and Venice this past June and we hired a guide for just the 6 of us to see the Colosseum and Vatican in one day. The company we hired: Miles & Miles and our guide Grace were excellent, but trying to do both in one day was too much, so your plan to split in two days is wise. Here is the link: https://www.milesandmiles.net/tours/rome/type/walking-city-tours?page=1. Note that had we done this all over again, we would have seen the Vatican in the early a.m. It was a zoo in the afternoon.

For Venice, I would highly recommend the secret passage tour from Walks of Italy. You get to see the Doge’s Palace, prison, and St. Marks and the tour is quite small, less than a dozen people. Our guide was from Venice and extremely knowledgeable. My friend is a contractor and wanted to know everything about construction of the cathedral and our guide was a wealth of information. We were amazed at the depth of her knowledge. Here is the link: https://www.walksofitaly.com/venice-tours/doges-palace-secret-passages-vip-tour

One other thing that I would like to suggest is that you consider taking a food tour. We took the Eating Italy Trastevere tour: https://www.eatingeurope.com/rome-food-tours/. Come hungry because this tour took us to little cheese shops, best Porchetta (ever), and a restaurant wine cellar older than the collesium. Our only regret is we took is on the Saturday before we left and our girls wanted to go back on Sunday to try some of the food shops and get some food for the plane on Monday and they were close. Check out the Eating Italy App for recommendations on restaurants as well.

In Venice, if you have time, I would also recommend Allesandro’s Bar & Cicchette tour in Venice. It is more of a bar crawl than food tour. Alessandro is delightful, a Venician, historian, and a very witty man. His site doesn’t seem to be operational, but here is his address: alessandro@schezzini.it.

For great food in Venice, check out Skye McAlpine’s blog. She lives in Venice, is a foodie, and just published a cookbook (which I can recommend). We used her blog to help us find some great places to eat Venician food: http://www.frommydiningtable.com.

Have a great trip,
Sandy

Just an fyi, viator is a reseller of tours, like expedia for hotels. If you find one you like on there, try searching google for the description, you will probably find one that is that exact match. I usually feel better dealing directly with a company than a 3rd party.

I have done Walks of Italy (and am looking to again I think for a new tour), and City Wonders/Dark Rome in a mix of Venice, Florence, and Rome. All were great.

Tickets for the Colosseum, Forum and Palatine hill here.

https://www.coopculture.it/en/colosseo-e-shop.cfm

Great free informative tours of Venice for your 13 yr old. You'll all learn a great deal about this city and the guides are a lot of fun.

http://www.venicefreetours.com

If you have the time, a trip into the lagoon to see the Mose Project would be worthwhile.

This is the project that will stop Venice from sinking further into the sea.

These are all great tips, and I really appreciate all your helpful knowledge! Thank you so much, I was afraid I would get a lot of, "That's just not going to be enough time, you need to extend your trip," or, "You should just drop Venice and focus on Rome if that's all the time you have."

We don't have the option of more time, if I don't work, I don't get paid, and taking off this much time is more than I can really afford already. I also forgot to mention, the reason we are heading to Venice is that we have a couple of friends from college who are flying in to Rome on Wednesday and immediately driving themselves to Venice, so we wanted to spend a couple of days hanging in the City of Canals with them. Their daughter is living in Rome and attending college there, so they have gone several times. They also told us to take as much time as we can, but this is all I can do right now. We will surely find more this time to plan to see next time.

I wasn't aware Viatours was a reseller... that's great info. I had heard the Dark Rome tour was good and was planning to look more into that. The Doge's Palace tour sounds interesting in Venice, we will need to look more into that one, as well.

Thank you again, everyone, and please, keep the tips coming!

I forgot to mention, in Venice, we are staying at the Hotel Bella Venezia, which is straight down Calle Bembo and Calle de Fabbri from the Ferry Terminal Rialto. We chose this for its central location and ease of passage on arrival and departure with our luggage in tow, as much as anything. This, after spending many hours comparing hotels online and finally becoming bleary-eyed and everything beginning to run together, lol.

You can definitely get overwhelmed with “must sees” in Rome, but it looks like you have a good plan for what your top priorities are and for the time you have. A whole day for the Colosseum, Forum, and Palantine Hill will still leave you evening time to wander. You could book directly for the Colosseum. And I think, with only 3 days, you CAN see St. Peter’s and the Vatican Museum on the same day, especially with a non-structured day between. You have gotten good advice on tours.

Venice is BEST without a lot planned. Wander, ride the vaporetto, stay IN Venice, and enjoy!

We did the Cicchetti tour with Alessandro in 2014- it was a blast! But it did involve a lot of drinking, not sure your 13 yo would enjoy. And if I am remembering right- I either read it here or he told us then, that he was retiring, so it may not exist anymore.

Try to fit in a ride up Campanile San Marco- the views and light were fabulous!

The only other thing I would say and it's probably not possible at this late date- give Venice the third night and fly home from there, saving yourselves the time/money getting back to Rome.
We loved Venice so much I am right now scheming how I can add it to what is supposed to be a "short 12 night trip" to Rome and Amalfi next May. Actually considering adding a few nights and training from Salerno to Venice, flying home from Venice. We shall see!

A visit to the Rialto Market is fun. The produce market there is closed on Sunday and the fish market closed Sunday and Monday. The markets open at 7:30 am and the fish market closes early (1 pm). The varieties and colors of all the fish are amazing.
Rialto Market also has stalls selling good snacks and souvenir items. It's a good place for a 13 year old to browse and he can find a reasonably priced souvenir.

One thing - since you arrive at 9:30 AM, I would get an early afternoon train to Venice on arrival day - then that jet lag day can be spent in a train and in Venice (more relaxing than Rome). Do your Venice time, then when done go to Rome. That way you finish in your depature city - saving one hotel change. One night stays never work out the way you want, and when at the end of a trip make your last day a bit of a waste.

Understood, Mira, but the hotels and plane tickets are already booked and non-refundable. There were some concessions we had to make, but it is what it is.

Ah. Flights booked wouldn't matter - my plan has you in Rome for your return. But hotels do, my suggestion would swap them - Venice first, then Rome. Given that, your plan is good. I like not having a ton of plans in Venice - it's great for just wandering.
As to tours in Rome, we like Walks of Italy. The Pristine Sistine tour is great, a little expensive, but well worth it. As you probably remember the Vatican area is super crowded, so getting to see the chapel before the crowds is quite the experience. The downside is that it's close to noon when you get to St. Peters. You skip the line (you go through the groups entry between the museum and the basilica), but it's still busier.