Just outside Rosendal there is a very nice waterfall called the Hattebergfossen, near the viewpoint Baroniet. This is the unofficial name but used by locals. Access is easy, so why don’t visit.
North of Rosendal there is the magnificent Furebergsfossen along road 551. This one you really shouldn’t miss. Also the hike to the Bondhusvatnet is a must to do. Besides the beautiful walk you also have a good view on some waterfalls like the Kroksfossen.