In Iceland, you can't just have a stunning lake. No, it also has to be inside of a volcanic caldera. And sometimes that's not even enough, so the showiest country in the world provides something like Kerid Crater Lake, which is a nearly neon blue lake sitting in a volcano surrounded by rare red volcanic rock.
Located in southern Iceland along the so-called Golden Circle, Kerid is unique among crater lakes in that its caldera likely didn't form from an explosion as most do. The Kerid volcano is thought have formed when the magma in the center simply depleted itself, and the empty chamber beneath caved in on itself. Regardless of the geological minutia that led to the lake's creation, its bright rainbow of colors look unearthly.
In addition to the bright, sapphire-colored waters, the steep slopes of the caldera's bowl are almost entirely covered in red volcanic rock. There is one, less-steep side of the slope that is covered in rich green moss, as though the lake weren't colorful enough.
The lake can be visited along tours of the Golden Circle, justtry not to lose yourself in it's beautiful blue eye.