Traveling to Rovinj in early October. We will have just one day there before moving on to Split.
What are the “must sees” in Rovinj?
Rovinj is a charming town, and just wandering the streets will be a joy. I seem to remember that RS has a walking tour in his guidebook and/or on his mobile app.
The one main sight you'll want to visit is the Church of St. Euphemia. And do climb to the top of the bell tower for spectacular views.
I also enjoyed renting a bike and riding around the harbor to the marina south of the old town.
Just walk around and take it all in. If you can find a 1-2 hour boat tour, go for it; this place just begs you to get on the water.