One of the most interesting musuems I've visited in Iceland is Eldheimar because it was built around the excavation of a house buried under lava rock and ash after the eruption of Eldfell volcano in 1973 on the Westman Islands.

All of Heimaey, the only island of the Westman Islands where people live, was covered in ash after the eruption and many houses, as well as streets were buried under lava. It was a scary night when the volcano erupted. Thankfully, there were no fatalities and many of the residents came back to clean up, rebuild, and live on Heimaey.

The items in the excavated home were left for people to see that the residents didn't have time to pack up anything. They literally had to put on their coats and shoes, and run out the door. Along with showcasing this house, the museum also shows how the shape and topography of the island changed after the lava cooled. On the top floor, you can learn about the volcano eruption on Surtsey.

I can't recommend this musuem enough and I hope you check it out while on the Westman Islands.