Any suggestions for day trip to Slovenia from Italy (Udine) by car?

[XelaM]

We are currently on holiday in Bibione, which is not far from Udine and the Slovenien border. We have a car, so were going to do a day trip to Slovenia, but unfortunately some of my family don't want to go all the way to Ljubljana (just over 2 hours away) and would prefer to visit somewhere closer to the Italian border near Udine. Does anyone have any ideas about places in Slovenia worth visiting around there?

Tolmin Gorges
Predjama Castle and Postojna Cave
Skocjan caves

Postojna caves are nice. I think we went to the Lipizzaner stud somewhere round there too. Those are the same type of horses from the Spanish Riding school in Vienna. Probably a bit niche if you aren't in to horses but I enjoyed it 😁

@Fivemoreminutes1 Thank you so much for the suggestions! Looking at the map it appears the Prejama Castle and Prostojna Caves are close to each other but a bit further from us than Stocjan Caves. If we only did one or the other are the Prostojna Caves worth the extra miles over the Stocjan Caves? The Prejama Castle looks incredible in photos.

@Weepingwillows12 Hah, my daughter is horse-mad and has a pony herself. In fact, she has made a hole in my head about how much she misses riding (we have only been away a week so far 🙄) so today we are going to the riding school in Bibione. She would absolutely love to visit the stud farm. Not so sure about the rest of the family 😬

The Skocjan caves are amazing so if you only did them, you wouldn’t feel like you were missing out.

Just to say a HUGE thank you for the recommendations! We went to the Prostojna Caves and the Prejama Castle and It was incredible!! Absolutely loved it and were hugely impressed not just with the unbelievable(!) sights but also with the Solvenian organisation. There are literally millions of tourists visiting there, but everything is so fantastically organised and streamlined that we didn't have to wait for anything and the tours and service at the restaurants/shops were fantastic. Even my usually unimpressed (with anything but her phone) 12-year-old loved it and thank ants to go back! I wanted to visit the stud farm as well, but we ran out of time and I was overruled by other family members. But Slovenia definitely left us wanting to ho back for another visit. 😃

...and wants to go back*

My 12-year-old even disregarded the fact that her phone couldn't get reception in the mountains so she couldn't get on SM all day 😱and extra benefit to Slovenia! 😆