Two smaller krater lakes right next to each other, each with its own vibrant turquoise/aqua hue. The lakes are very easy to reach and you can park right next to them.
About a 9km drive from the 1 road, which shouldn't take more than 10 minutes. From the 1 road take the exit to '863 Krafla' (GPS coords: 65.645175, -16.797347). There's also a sign-pole saying KRAFLA. Just follow this road passing the steaming powerplant and the lonely outdoor shower.
The drive up is beautiful with steam coming from the earth all around you.