Kerið is not just a stunning lake. It is a lake inside of a volcanic caldera (a caldera is the center of a volcano). The water is a nearly neon blue and it is surrounded by rare red volcanic rock.
The area around Kerið is not hilly anymore so it is hard to imagine that thousands of years ago this lake was an active volcano.
There is a possibility to go down to the water. The pathway is not steep and easy to follow.
The lake is located along the Golden Circle. The entrance and an informational brochure will cost you 400 kronur.