Leaving Zagreb, we stop at the fortress town of Karlovac on the River Kupa, before continuing to one of Europe's natural wonders - Plitvice National Park. We explore this scenic wonderland of 16 inter-connecting lakes, flanked by thundering waterfalls and primeval forest. We visit Korana Canyon to see the 230-feet high falls and Tomicevo Pogledalo for panoramic views over the park. (BB, D)