Slovenia itinerary

I prefer to limit my hotel/apartment changes, so I would add a night to Ljubljana and just do a day trip to Lake Bled from there. Lake Bled is lovely. We rented a boat and rowed to the island. Walked around the lake. Had lunch (and cream cake!) at a restaurant on the lake with a view of the castle. Drove up to the castle, but just for the view, we didn’t explore much. We even stopped at the adventure park (but my kids were too old for most of the rides so they didn’t go on any). Then we drove to Vintgar Gorge around 3:30 and had the place to ourselves. It was an easy drive (less than an hour) back to Ljubljana. The city is really charming, especially at night. I think it has more to offer than Bled, as far as restaurants and atmosphere.

Kobarid and that area are stunning. The views from the outdoor WWI museum are amazing. We didn’t drive the pass due to carsickness, but the drive along the river is really gorgeous.

We really enjoyed Postojna Cave. Again, easy day trip from Ljubljana, or you could stop on the way from Kobarid to Piran. Or day trip from Piran.

I agree - I would add a night to Ljubljana (which is a charming little city) and day trip to Bled. Lake Bled is lovely but the town is nothing special. I'd rather be in Ljubljana at night. Plus, if you have possibly rain one day, if you day trip to Bled on the nicer day if that's an option.

Consider the scenic route from Ljubljana to Bend via the charming little town of Skofja Loka, then take the twisty road up through the mountains via the tiny towns of Drazgose and Kropa, with breathtaking scenery down below as you drive.

Piran is lovely, but three nights there might be too many unless you just want to sit back and enjoy a little beach time or something. If in doubt I'd take one of those nights for the beginning of the trip somewhere.

Slovenia... good choice!

Bohinj's Kravji Bal (Cow's Ball) is expected to happen Sept 18. This is a one-day festival celebrating cows being brought down from summer grazing pastures. Cow parade. Folk Music. Dancing. Power Equipment. Food and craft vendors. It's great fun. Bohinj is only 45-60 minutes from LJU airport, so it makes a perfectly fine end-of-trip stop.

Caves: Postojna is more of a developed amusement attraction. Škocjan Caves is more natural. All the Slovenians with whom I discussed the caves recommended the latter. It was great!

Food: I highly recommend the LjubljanaYUM food tour in Ljubljana.

I could go on, but instead I will point you to my Slovenia trip report, which hits all your anticipated stops: https://community.ricksteves.com/travel-forum/trip-reports/25-days-in-slovenia

Ljubljana, Bled and Piran are all enjoyable. The number of nights needed depends on what you want to do and if you're going to daytrip. We stopped in Bled on our way to Ljubljana (from Salzburg, Austria) for about half a day. Then we spent 1 night in the latter and later 2 in Piran. Wish we would have had 1 night in Bled, 2 in Ljubljana and the 2 we had in Piran was about right. BTW - Rovinj, Croatia is similar to Piran but a little better/nicer IMO.

Thank you ALL for your helpful comments and suggestions re: Slovenia itinerary.
I think we'll not stay the night in Bled, but see it as a day trip or on the way to Bohinj.
Also, sounds like 3 nights in Piran is one too many. I was thinking of one day to enjoy the seashore, and one day for a day trip to Skocjan Cave, but seems like we could see the cave on the way back to Ljubljana. Are there any other towns or sites on the way back to LJU that anyone would recommend?
Also, has anyone crossed the border to Rovinj? Sounds like it's more of a gem than Piran, but I'd hate to get stuck in a complicated and bureaucratic border crossing. Any thoughts?
Also, I rarely hear about anyone traveling to eastern Slovenia? Are most of the interesting sites and spectacular nature located in the western regions?
Thanks again!
P.S. Yes, it was confusing the way I mixed up days and nights - duly noted!

Mermaid, I have been to both Piran and Rovinj but on different trips. I crossed between Slovenia and Croatia by train and that was before Covid, no idea what crossing that border is like right now for someone not from the EU.

Piran and Rovinj are both gems. They are both Venetian towns (still bilingual). I might give the slight edge to Rovinj, but I wouldn't say it is far superior to Piran. If you had more time, I'd recommend a few more days to see Croatian Istria including not just Rovinj but some of the hill towns. But it sounds like you really don't have the time for that - and I wouldn't hassle driving down there just for Rovinj alone. Stick to Piran this time.

I've been to a few of the eastern Slovenian towns. I spent a few nights in Maribor and day tripped to Ptuj (oldest town in Slovenia) and Celje. All are nice towns and far less touristy than anything in the west. (And really, other than Lake Bled, Slovenia doesn't seem very touristy at all compared to say Italy or Austria.) Ptuj is a nice little old town, with a beautiful castle on the hill. Maribor is much larger, Slovenia's "second city" and has some charm but nothing like the "fairy tale town" feel of Ljubljana, which feels positively magical at night, with all of the bridges over the little river lit up at night. Maribor just doesn't have that but it's still worth visiting...if you have time.

My original plan for my 2019 trip was 14 days in the former Yugoslavia... then narrowed down to 14 days in Slovenia... then narrowed down to 14 days in western Slovenia... then expanded to 25 days in western Slovenia. I kept finding things that I really wanted to do in the western half of the the country.

Things happening in Piran in early September include the Tartini Festival and Neptune's Baptism, the initiation of new students into the area's maritime secondary school which includes pirates taking over Piran. Or hang out with Saša, riding around the coast in his vintage car.

Are there any other towns or sites on the way back to LJU that anyone
would recommend?

Predjama Castle is a favorite site for many (more to see the outside than the inside)... very Instagramable. But... I really liked the Park of Military History at Pivka -- a former Yugoslavian military base converted into a museum. It's the place where Yugoslavian tanks rolled from to put down Slovenia's declaration of independence. There is a nice part of the museum that chronicles the movement from part of Yugoslavia to independent nation.

In July of 2017 we drove from Ljubljana to Rovinj, spent a few nights, and then drove back up to Piran. It took over an hour to cross into Croatia but the cross back into Slovenia was much quicker (we did take a different route). The Croatian hill towns of Motovun and Grožnjan are also worth a stop if you have time.