Motovun is a nice little hilltop town in the heart of Istria. The town is Venetian, with complete town walls around the tiny core as the main feature. You can walk the walls for a fee and enjoy the views. The specialty seems to be truffles. There are a few shops selling them.

If you drive to Porec from Italy and want to avoid buying the vignette, Motovun is actually on route between the Slovenian border and Porec, just 45 minutes from Porec. There is a huge parking lot at the bottom of the hill. For an additional fee, you can use a shuttle bus to the hilltop. I opted for walking instead. It is a steep but nice walk through the town. All in all a nice detour to spend a few hours, but nothing that would be worth an entire trip.