This is a design of a
board used for games carved in wood and found in a Viking grave in
Uppland, Sweden. Such a board was called hnefa tafl.
According to Biedermann this game was called mill, and the structure of the board is found on many rock walls in Austria, Italy, France, England and the Balkans: "On the rocks it not only occurs on horizontal surfaces, but also on vertical rock walls where nobody could have played a board game on it. Therefore the structure could not only have been seen as a game board, but must also have had a symbolic meaning."