Finnish treasure-flame and aurora folklore
Finnish has several words for the same light and they all mean roughly the same thing: aarnivalkea, virvatuli, aarretuli, aarreliekki. Treasure fire. It is the northern version of the will-o'-the-wisp, and unlike most such lights it comes with a specific and mercenary explanation.
The story is that a person burying treasure did not simply hide it. He bound it, so that it could only be recovered at the summer solstice, and set a flame over the spot to mark exactly where and exactly when, so that he could come back for it himself. The flame burns permanently and is protected by a glamour, so nobody stumbles on one by accident.
The way past the glamour is the best detail in the whole tradition. You need the seed of a flowering fern. Ferns do not flower. The seed of a fern in bloom is the standard European folk shorthand for the impossible object, and it is picked on Midsummer night. Carry it and it will lead you to the treasure fires, and it makes you invisible into the bargain.
Finnish belief also carries the liekkiö, the flame spirit, understood as the soul of a murdered child, and the two ideas sit close enough together that the lights get confused between them.
Underneath all of it there is real phenomenology. Marsh and bog gas ignites, and Finland has an enormous amount of marsh and bog. People walking home across mire at night in the light summer dark saw something, and the tradition explains it.
The pin sits in the Finnish Lakeland. If you are there around Juhannus, the midsummer festival, the whole calendar of this is still being observed, with bonfires instead of buried gold.
The forests and lakes of central Finland
See it on the map
Other places on the map within a couple of hours.
