Looks like grapevine growing up the wall. Is this castle in Kal
just south of Pivka?
No, if you go from Pivka towards SW, you reach Kal village. But for this castle you drive from Pivka towards SE (towards Knezak). In Zagorje village you turn eastwards and reach the tower in some 1000 meters (it's seen from the road). And - it's abandoned.