If you try to imagine how the heaven looks like, than you shoud go to see Plitvice lakes.
Something so beautiful, just so beutiful.
This trip will take whole day.
If you decide to go to Plitvice I recomend to go in the middle of the week, tuesday or wendsday are good days. On weekend is to much trafic on the road.
By car, you need about 4 hours of driving. The was that I will recomend to you is 320 km (Pula - Rijeka - Karlovac (on the way to Zagreb) - Slunj - Plitvice) the map is HERE. You shoud start the trip very early in the morning. The trip will take 4 hours, and you need at least 4 - 5 hours on the lakes, and than you will see just the half. There is restorants in the park, and you coud take
In Plitvice there is one small driving with train (depens which entrance you take), also you will have driving with boat. Walking track are on some part wet. You need to have SNEAKERS.
More about the Plitvice Lakes, entrance tickets and parking information you can find on official web site http://np-plitvicka-jezera.hr/en/