We just have 4 days to travel around Slovenia and/or Croatia coming from Venice mid September and wondered where we should focus our attention? We will be using public transportation but would like to find day tours in whatever city(ies) we stay stay in. Any suggestions for an itinerary? We would love to see Lake Bled if weather will be nice and Plitvice if time allows.
I would spend all four days in Slovenia instead of making the longer trip to Plitvice. A car would give you more freedom in the rural areas, but Lake Bled and Postojna caves, for instance, are well served by bus from Ljubljana.
From Venice, the most direct ways to reach Slovenia are the www.goopti.com shared shuttle service or the once daily, scheduled bus by www.drd.si between Venezia Mestre station and Ljubljana. Trains don't cross the border at Trieste, but buses (not on Sundays) or taxis do, for instance if you wanted to pick up a car at Portoroz and drop it in Ljubljana.