Kobarid to Rovinj

The drive from Kobarid to Rovinj is less than 3 hours, so that gives us a lot of time along the way to see some of this stuff before we cross the border into Croatia

Skocjan Caves

Predjama Castle

With detours to these three spots, and time spent exploring each, I imagine it will be a long day.

With three nights in Rovinj, even if we arrive late, there should be plenty of time to explore the town and do a good driving tour of the Istrian peninsula.