Brocken spectre in Central Balkan National Park, Bulgaria

© Maya Karkalicheva/Getty Image

A ghost on the mountain. Brocken spectre in Central Balkan National Park, Bulgaria

With Halloween around the corner, we present the ghostly image of a Brocken spectre. Despite appearances and the season, there's nothing paranormal about a Brocken spectre. It's the magnified shadow of an observer cast in midair upon a cloud opposite a strong light source. Brocken spectres are rare but climb a mountain at dawn up to the misty slopes and you may be fortunate enough to witness the effect. The spectre, also known as a Brocken bow, mountain spectre, or spectre of the Brocken, can appear anywhere in which conditions are right—like here in the Balkans of Bulgaria. But it's the thick fogs of the Brocken, a peak in the Harz Mountains in Germany, from which the phenomenon draws its name.