Seven kilometres north-east of Porec, just off the road to Visnjan, the limestone karst opens into a 132-metre-deep show cave that has been guided since 1995. The descent takes you through five chambers, each with extraordinary calcite formations — including a slender column known as the "Snowman" and a chamber where stalactites and stalagmites have almost grown together over millennia.
Tours run hourly through the summer and last about 40 minutes. Bring a jacket — the cave stays at 14°C year-round. Combine with the Parenzana trail, which passes nearby, for a half-day out of town.