In Croatia you should
definitely go to
plitvice lakes, what a wonderful place. The downside is that you can't go for a swim there. A solution for that would be
Krka lakes where you can actually go for a swim in the lakes and waterfalls The
walls of
Dubrovnik are also quite nice.
When (or if) you get to split, you can take a ferry to the island "Hvar" (to Stari Grad) and then go across the island. It has quite a view and the roads are fun to drive. Then you take another ferry from Sucuraj to Drvenik and continue to Dubrovnik.
In Montenegro we lived in Herceg Novi. You can rent a boat in Herceg Novi and go to the
blue cave . On the way back you can go to
Mamula fort. Then you could go around the Kotor Bay to Kotor. There's an
old castle. It is one heck of a climb but the view is breathtaking. We also bought a tour to
Tara canyon. It included sightseeing and rafting. Absolutely recommended. I can give you the contacts of that travel agency.
In Albania we lived in Sarande. Open up google maps and you can see Vlore. We used that road which goes nearby the sea to get to Sarande. The road is awesome and the view is outstanding. You could go to Butrint national park to see the
ruins of Butrint. Also you can go to
Gjirokastra Castle. If you like army stuff you should definitely go there. It has a museum of many artillery guns, a tank.
I can also give you photos of the places I described. Or you can use the internet