Plitvice Lakes

Over the weekend I saw a Nature program highlighting Croatia's Plitvice Lakes National Park; it's a UNESCO World Heritage site, and appears to be very biologically diverse and picturesque (do a Google image search to see for yourself). The Nature program (as usual) focused overwhelmingly on the vertebrates; I'd love to get a chance to see the invertebrates (not to mention organisms from the other five kingdoms) that were there.