Please note that from 2005 there are two possible roads between Zagreb and the coast. If you are using some older guidebook you might get confused when you read that Plitvice are halfway from Zagreb and the coast.
D1 road is the old road, 2-lane only, going from Karlovac via Plitvice and Knin to Split.
A1 road is a new highway that runs on a big loop around Plitvice and does NOT pass nearby. If you wish to visit Plitvice then get off from the highway in Karlovac and take the old D1 road. (Btw. D1 is quite a good road, so no need to be worried about this "old" thing).
Another warning concernes trains. If you examine the list of stations between Zagreb and Split you will notice a station named Vrhovine-Plitvicka jezera. Please note that this is VERY FAR from the entrance to the park and that there is NO ORGANIZED TRANSPORT! So, you don't want to take a Zagreb - Split train and end up in the middle of nowhere! (Luckily, ICN trains don't even stop here).
If you are on the public transport, then take the bus BUT MAKE SURE IT TAKES THE D1 ROAD - buses running along the A1 are of no use.
This must be a big temptations for those who are pasionate fishermen, there is a plenty of fish in the lakes, especially trouts in the Lower Lakes, and yet, fishing is not allowed in the whole area of National Park.
IIn case of the sudden rain or bad weather, you can take refuge under such a wooden shelters which are situated all over the National Park. If you cannot find this shelters, the best is to search for the inner road of the park where the bus stations are situated, all of them with the same kind of the shelter.
There can be a lot of snakes, so better beware...
Also, wild animals like woolves or bears are also very common! So, don't wander alone in the deep woods and very late at night, be sure to leave the park before closing. And preferrably, stick to the marked paths.
once upon a time (has it changed by now?)the legendary lonely planet wrote that there were free buses one could use to visit the park. fact is that buses never quite existed. there are some sort of electrical vehicles that do transport people from one parking lot to the other - but they do not take in the park and the plakes. Basically if you want to visit the park, you'll need to do it by your own legs - so if you can't walk for around three hours, you might as well decide not to visit it... 'cause you really won't be getting near any lake. try again, Lonely Planet - and provide the correct facts