Krka national park
Apparently, (we left by car, from the top of the falls, but I don't know if there is an entrance there, or just a way out) there are two ways to reach the falls: by car, or by boat.
We did it the second way, and I think that is is the most pleasant way to do it.
The boat ride is short and the landscape is beautiful. It's a pity we had no time to explore the upper lakes.