Since the 1940’s (possibly earlier) there has been a strange light phenomenon observed in the Hessdalen Valley, Norway. The spectacle has a form of white or yellow light of unknown origin standing or floating above ground level. Between 1981 and 1984, the lights were observed up to 20 times per week but have drastically reduced in frequency since then to about 10–20 times per year. Despite ongoing research and numerous working hypotheses, there is no convincing explanation of the origin of these lights.