Via Atlas Obscura:

The “elfin lady stone” was actually covered up back in 2015 after road work was conducted to clear a landslide near the town of Siglufjordur. The rock, which according to local folklore, was sacred to the elves, was buried without the workers even taking much notice. Until the calamities started.

Tolkien notwithstanding, the elves of northern Europe have kind of a shady reputation in folklore. Just saying.