How much time is Istria really worth? We will be spending a lot of time in the south of Croatia (Dubrovnik, Hvar, Korcula) and have 5 extra nights to spend in Istria and/or Slovenia. We are trying to figure out how much time to devote to Istria or whether we should spend most/all of our remaining 5 nights in Slovenia. (Either way, we will be stopping at Plitvice Lakes on the drive up!)
Your instincts are spot on. Having traveled from Opatija, through Pula and overnighting in Rovinj, the Istria Peninsula is skipable * if * you have the choice of diverting 5 nights to Slovenia.
IMO, Slovenia trumps it! We spent 6 nights and could have easily spent more time in Slovenia.
From Plitvice, head to Opatija, then up to Slovenia.
Plan one night near the Lipica Lippizaner horse farm, Postojna cave and Predjama castle.
Schedule a quick stop in Skofja Loka on the road to Bled.
Spend 2 nights in Bled. Don't miss the beekeeping museum in nearby Radovljica!
Spend a night in Ljubljana.
Are you planning on dropping off your Croatian rental car in Zagreb?
I mostly agree with Diane. I'd spend more time in Ljubljana--2-3 nights if possible. Also agree that the Bee Keeping Museum is worth a visit!
Thank you for your comments! The more I look into Slovenia the more convinced I am that we need to spend sufficient time there.