Hi! We have been to Croatia several times and will soon be going back in around a week. We have been to most regions, except Slavonia. This time home base is mostly Rijeka. We will be taking several trips to Istria and likely also Krk, where we have spent time. In Istria, we have already been to Gronznjan, Motovun, Rovinj, and Novigrad - we have hit some of the wineries in the area too, really enjoying Malvasia and Teran. We will certainly be going back to some of these places this time. Also have one more day that is flexible to spend on a day trip to Istria and trying to decide between Pula, Porec (a wine festival going on) and Vrsar (a fisherman's festival going on). We liked Novigrad so much, we might combine with either Porec or Vrsar. If we did Pula, we would probably just to that for the day. Will have some older folks with us, so don't want to over book. Any thoughts? Thanks!

It really depends on what you want to see and do, but FWIW, I loved Porec. The mosaics of the Euphrasian Basilica are spectacular.

Are you committed to staying in Rijeka? If not, you might consider nearby Lovran -- very low key, a bit in need of renovation, glorious lungomare.

The Vrsar fisherman festival is really fun, but I don’t think I’d want to pass up a wine festival….

It's really up to you.
May be you check the Slovenian neighbourhood with
the caves of Skocjan/San Cassiano, Postojna
the stud of Lipizza
the small town of Pirano
or the WW1 and WW2 sies more in the North.