@Laščan
The start of the path through trenches and 300m long cave begins shortly after the road from Preval starts ascending to Sv Gora. At the first parking lot, at the first (?) station of the way of the cross, turn left and continue following the marked path.
At the top of Sv Gora only one path branches off to the south; descend it and at the first junction follow the sign to the mausoleum - from the junction to the top approx. 20 min.
From Sabotin you'll hardly make a circular path to Sv Gora and Škabrijel; I suggest circular path Nova Gorica/Solkan - Sv Katarina ("Kekec") - Škabrijel - Preval - Sv Gora - Vodice - bend on Solkan/Preval road - NG/Solkan.
Lp, Filip.