The Big Waterfall at Plitvice National Park, iced over
Plitvice National Park, a maze of waterfalls and seemingly unsupported bridges over lakes, is Croatia's most famous attraction. And, it's beautiful. Really, really beautiful, even in the middle of winter (or maybe especially in winter) when the waterfalls freeze over into strange forms and the lakes reflect the white snow.
Plitvice is about two hours from Zagreb and two hours from the Istrian peninsula. It's an easy drive from Zagreb (where you'll probably want to rent a car anyway), or there are frequent tour buses that go from Zagreb to Plitvice. Once in the park, you can take Path A or Path B. Path A will take you on the upper trail above the bridges and lakes which is where we got these views. Path B is more interesting because you can walk on the thin bridges that float around the lake; we didn't go on that walk because we had the dogs with us. Dogs are welcome everywhere in Plitvice though they must be on leash (but keep in mind that many of the paths are quite narrow or steep so it can be a difficult path to walk with a leashed dog.)
Even though it was quite cold while we were there, there were many tourists and I suspect that in the summer, it will be absolutely packed with tourists.