Italy in early October

Some find just seeing the Colosseum from the outside to be enough. The Vatican Museums get really crowded, there is no such relaxing visit when it is open to the general public; if you don't know what is in there from your research, go with a tour guide and they will dictate the time it will take. Otherwise, visit as long as you can until you feel complete.

To get to Pompeii take the train to Naples. This takes an hour from Rome.
At Naples, transfer to either the Circumvesuviana (buy the ticket roundtrip at the ticket booth cash only) or the Campania Express ( you can buy this in advance at

https://www.eavsrl.it/web/campania-express-en )

They both stop right near the entrance. The stop is Pompeii Scavi.

I will be in Croatia on a sailboat for 2 weeks before getting to
Rome, so getting a timed ticket to Colosseum etc may be difficult (not
sure if I will have wifi access), but at least I'll be in the same
time zone. If I can't get a timed ticket for the colosseum is there
any other option to see it? Is it still crowded in early October?

Yes. October is still high season in Rome and will be crowded. You need to book your timed-entry tickets to the Colosseum WELL before you get to Rome. Look to do that around 30 days in advance of arriving in Rome, and don't count on being able to land tickets that include the underground. They are THE most in-demand tickets for any attraction in Rome and sell out quickly once becoming available. You are not allowed to access the underground independently so it'll be either via narrated tour or simply accompanied by a staff member. You can 'do' the Colosseum + Forum and Palatine on a timed-entry ticket in one day if you get started early.

...how much time should I allow for the Vatican Museums and Sistine
Chapel? Morning tickets are nearly sold out, and I'm wondering if I
should instead opt for an afternoon ticket for a more relaxing
experience?

Neither will be "relaxing". The main route from entry to Sistine will be very crowded at both times of the day. Book whatever time works best for your schedule. How much time to spend depends on how much interest you have in what's along the way. I'd set aside at least 3 hours.

Pompeii from Rome: The best way is via fast train from Rome to Naples (abt 1 hr, 10 minutes) and either Circumvesuviana commuter train or escorted tour from there. The worst way (IMHO) is one of the bus tours from Rome that takes nearly 3 hours one-way just to get there and then spends only 2 hours or so at the scavi before heading 3 hours back. Many of us will recommend seeing the ruins at Ostia Antica which are smaller + much closer and easier/less expensive to get to from Rome than Pompeii.

Look to do that around 60 days in advance of arriving in Rome...

Tickets to the Colosseum go on sale 30 days prior to the target date, yes? Right now [00:27 PDT 7/14/24] tickets are available through August 13. So buy your Colosseum tix before departing for Croatia.

The purpose of the 48 hour ticket is to give you more flexibility - many prefer to do the Colosseum and then Forum on separate days. You can do them on the same day if you wish. The disadvantage of the 24 hr pass was that if you had an early morning Colosseum entry, you couldn't enter the Forum in the afternoon of the following day.

And yes, it will be crowded in October - it was crowded back in November when we were there.

Tickets to the Colosseum go on sale 30 days prior to the target date,
yes?

Arg. Yes. Mixed it up with release dates for Vatican tours, which are 60 days in advance (general-entry tickets are on sale through the rest of the year.) Thanks for catching that, Mark; I've made the correction.

Kathy and Mark, I have spent quite a lot of time in this forum since I posted the first question. Kathy, I found your earlier thread with lots of details about the relatively new ticketing system. Thanks for posting all that, it's clearer now. I'd spent a lot of time messing about on another site that maybe was the OLD colosseum site; it was a dead end, and the site came up to click on links to tickets, then it would just go dead after a while. Then I came across the Coop site that I now know is dead also, so the RS threads here were very helpful. I have my calendar marked to log on at the appropriate time at the end of August. IMO, it would be helpful if the sites that are now dead somehow got cleaned up and removed to cut down on the confusion, but that won't happen! ;-)

Mark, thanks for the explanation of the 48-hours, that makes sense; there isn't much price difference between the two anyway.

I got my login for the official site, and now that I'm playing with it, I see what some others mentioned. I picked a random date/time (not appropriate for my trip yet) that showed 1 tour in English available, and when I added 1 person it came up with no tickets available, yet when I backed out to the prior screen, the date/time is still available. that doesn't make any sense to me; either it's available or it's not...?

I'm also struggling with what the tix cover. I've done searches online, but most of the information (here, on TA, or Reddit) is from 1-6 years ago, so things certainly could have changed in the interim...
First, there are 2 portals, one says Guided Tours, and the other says Individuals, but both show "Full Experiences" as options. What's the difference? Is the Guided tour only if you're bringing your own guide? I seem to recall something I read in this forum about that, and when it's time to pull the trigger, I don't want to be messing around with unsuitable options! ;-)

Also, if a ticket gives access to "colosseum" but doesn't state anything else, what is available? is there an audio tour included? The next level (Full Experience) says "colosseum + arena" - how is that different? Then there's FE "colosseum + arena + underground" which makes sense, then there's the FE w Attic, that says it's "colosseum + attic" but doesn't show the arena as part of the admission. The last 3 (all Full Experience) are the same price. Can you enlighten me at all?

It's surprising to me what a black-hole-time-suck it is to plan a few days in Rome. I think I've already spent more than a few days just trying to figure this out. Colosseum is important to get scheduled, but you really can't wait to schedule the rest of the trip until 30-days out, or Vatican and any other popular sites will be closed out. I'm also trying to fit Pompeii in there, but can't figure out which 48-hours to leave together for Colosseum. Ostia Antica is looking more appealing, just for the simplicity and relative ease of getting there....

As always, appreciate any input!

We were in Italy for the first time last October for three weeks. If you wait until the last minute all attractions through the attraction website is sold out. So buy everything early if you do that. I personally was afraid if I waited until it was open 30/60 days before it would sell out or the times wouldn’t be favorable.
So we used Get your guide for a lot of tours mostly because it gave you the ticket to get in and skip lines. We were able to get one that included the colosseum plus the underground and palentine hill. It’s a skip the line. Our tour ended at the colosseum and afterwards you can stay inside as long as you want.
We used the same thing for the Vatican also. Lines are huge to get in so we found the get your guide tour with a skip the line was well worth it. You don’t get to spend a lot of time in the museums but had access to the Sistine chapel and skip the line into the basilica as well.
Enjoy your trip. Italy was one of my favorite places we’ve been to.

We were in Italy in mid-October and it was still very crowded and 30 degrees.

We hired a private guide for the Colosseum and found that the easiest. She organised all of our tickets and there was zero queuing. She took us through the underground area, which was well worth it, as well as the Forum. I got so much more out of the Forum with a very experienced guide explaining everything than I would have without her.

We did Palatine Hill later in the day and fitted it all in easily, including a leisurely lunch at a restaurant the guide recommended to us.

IMO, it would be helpful if the sites that are now dead somehow got
cleaned up and removed to cut down on the confusion, but that won't
happen! ;-)

Pat, the only official site for Colosseum ticketing before the current one was Coopculture, or at least for quite a number of years. It is not "dead" because while they no longer handle ticketing for the Colosseum, they do for some other attractions.

I picked a random date/time (not appropriate for my trip yet) that
showed 1 tour in English available, and when I added 1 person it came
up with no tickets available, yet when I backed out to the prior
screen, the date/time is still available. that doesn't make any sense
to me; either it's available or it's not...?

Your problem is probably because there was only space available in that time slot for 1 person, not 2.

Please, do not use ANY information for the Colosseum on any other website that's more than a few months old. It won't be current anymore. The new site (https://ticketing.colosseo.it/en/) and ticket/tour products just went live this past spring, and some new products - such as night tours- have been added very recently.

You do not want products under the "Groups" category as you are only looking for a couple of tickets. You want either the "Tours" or "Individuals" categories. They really do describe what the individual tickets include - or not - fairly well. For instance, the € 24.00 "FULL EXPERIENCE TICKET WITH ENTRY TO THE ATTIC OF THE COLOSSEUM" does not mention the arena (which is the partial floor over the underground) because that ticket doesn't cover access to it.

"COLOSSEUM - GUIDED TOUR" is a guided tour of the 1st and 2nd levels but does not include access to the arena, underground, attic or SUPER Sites at the Forum/Palatine.

€ 24.00 "FULL EXPERIENCE - UNDERGROUND LEVELS AND ARENA" includes an accompanied (by a Parco employee) visit to the underground at the booked time but it's not a tour...meaning the individual won't be providing narration. It also provides access to the arena + SUPER sites at the Forum/Palatine.

Just read the info for all ticket options carefully.

I'm also struggling with what the tix cover...

There is more information available on the official Colosseum web site - but it appears that it can only be accessed during business hours in Italy:

https://colosseo.it/en/area/the-colosseum/

I was able to access it late last night and did see details that I didn't recall being available on the ticketing portal. If you haven't been to it, you would have to access it either late at night or early morning, depending upon your time zone.

It looks like they now have an app, which appears to offer geo-located narration when you're there - this may be a replacement for the audio guides that were included with our tickets when we visited back in November. And there is also the Rick Steves audio guide.

The web site is still maddening in that there don't appear to be any detailed maps of the Colosseum or Forum - nothing showing the locations of WCs, limited food vending, etc.

Finally, it looks like the moonlight tours are once again available - we took that and it's a great way to avoid crowds - we also did the standard daytime visit.