Thanks for the feedback!

I just googled the walking directions from the port in Old San Juan to El Morro, and that's roughly half the distance. We've easily done that walk in the summer heat of Puerto Rico--there and back--so I think we can likely make it if we pace ourselves and take breaks. We can always develop a Plan B if necessary.

Not in the summer.

I think that would be a long walk. We stayed near piazza navona and I walked home from the Vatican — it was a nice walk over the bridge and I stoped for pastry. Another day I walked to/from the colosseum. That felt like a longer tiring walk even though I stopped for pizza and gelato. It is mostly pretty scenic except for a bit going through the commercial shopping district. So I think it’s doable if you are big walkers but might be better to split up into two days walk.

It's very easy to do. If you're traveling in the summer, try to not walk in the middle of the day.

If you're not a person who walks much, then sure it may be a challenge. But for a moderately fit person, walking to all the sites is the best and easiest way to get around Rome.

Yes, we walked all over, but we went over Thanksgiving so the temp was in the 50s-60s.

My kid nearly melted under the Roman sun one summer. You might take the heat into account.

Yes. We walked it with our kids 2 summers ago. It was long and a bit circuitous but fine. We are big walkers and think nothing of an hour walk however. YMMV.

I don't know if we did that exact walk but we really did walk all over the place all day long. With tweens.

There are famous buildings and attractions all over the place.

A guidebook map will show you what you need to know.

Google maps says it’s an hourlong walk. Anyone done it? Is it scenic and the sort of thing you can do gradually?

My hotel is 4km to the Vatican, located by the touristy stuff in Rome.