<P> In Scandinavia, cairns have been used for centuries as trail and sea marks, among other purposes . In Iceland, cairns were often used as markers along the numerous single - file roads or paths that crisscrossed the island; many of these ancient cairns are still standing, although the paths have disappeared . In Norse Greenland, cairns were used as a hunting implement, a game - driving "lane", used to direct reindeer towards a game jump . </P> <P> In the mythology of ancient Greece, cairns were associated with Hermes, the god of overland travel . According to one legend, Hermes was put on trial by Hera for slaying her favorite servant, the monster Argus . All of the other gods acted as a jury, and as a way of declaring their verdict they were given pebbles, and told to throw them at whichever person they deemed to be in the right, Hermes or Hera . Hermes argued so skillfully that he ended up buried under a heap of pebbles, and this was the first cairn . In Croatia, in areas of ancient Dalmatia, such as Herzegovina and the Krajina, they are known as gromila . </P> <P> In Portugal a cairn is called a moledro . In a legend the moledros are enchanted soldiers, and if one stone is taken from the pile and put under a pillow, in the morning a soldier will appear for a brief moment, then will change back to a stone and magically return to the pile . The cairns that mark the place where someone died or cover the graves alongside the roads where in the past people were buried are called Fiéis de Deus . The same name given to the stones was given to the dead whose identity was unknown . The Fieis de Deus or Fes de Deus are, in the Galician legends, spirits of the night . The word "Fes" or "Fieis" is thought to mean fairy, the same root as "fate" (fado), that can take the same meaning as the proto - Celtic * bato -, meaning "death". </P> <P> Cairns are also common on the Mediterranean island of Corsica . </P>

What do stacked rocks on a trail mean