There are many figures that animate the legends of Norse folklore, such as the Hidden People and the Trolls. Many Icelanders still grow up hearing the stories today. A high percentage of the population believes in these stories, but even those who don't believe prefer not to risk it.
The presence of all these creatures can be felt at any time of year, either immersed in nature or Icelandic cities at night. But the energy is especially strong during the month of December.