Brúarfoss (bridge falls although blue falls would work too) isn't a large waterfall but between the blue color and the shape it really is a unique sight. It's a little tricky to find but worth the effort.
Any comments are welcome.
I had made it a mission in Iceland to find this little blue waterfall, tucked in next to some vacation homes in Southern Iceland. Here is a wide angle showing the light of sunrise hitting the mountains in the background.