My second post from beautiful Croatia shows the heaven that is the Mljet National Park where the water really is that light blue. It's due to the lake bed which is made up of light coloured rock and the water is very clear. Not to mention lovely and warm on top so you can just float there for hours! We took a boat out to the 'island within an island' - an island on the lake which has a small monastery and cafe and spent the afternoon lazing around.
We also went ziplining! Something else I've never done before and actually not as scary as it looks. Although I did have plenty of trouble learning how to stop (I actually never mastered it and almost got kicked off the course when the instructors had to keep catching me at the end - whoops!). One more Croatia post coming.