I strongly recommend a visit to the Mljet Island on the Adriatic coast. That is one of the most beautiful places one earth one can imagine! And something else - take a few days to discover it and enjoy!
www.soline-mljet.biz.hr
Here you can find a lot of useful information about Mljet as well as about accomodation
There is a renewed Mljet accommodation site that I have just found at www.mymljet.com. This page has an availability calendar too.