While Croatia always gets kudos for the Adriatic Sea, its rivers and their flora and fauna are just as impressive. You can witness this at Aquatika, the freshwater aquarium in the town of Karlovac. The town is poised on the crossroads of four rivers so there is hardly a better place to explore the underwater world. The aquarium showcases a division of river into the upper stream, middle flow and lower stream, but also standing waters like ponds and swamps. Meet endemic species of fish, invasive species, and learn about the making of tufa – the wonderful stuff that waterfalls are made of.