In Isle of Lewis (Outer Hebrides, Scotland) are located some of the most impressive prehistoric megalithic structures in Europe. The most important sites are around the area of Callanish and include stone circles, cairns and stone alignments. The goal of Callanish is to align a certain number of stones or stacks of the same colour horizontally or vertically along any file or rank of the board. The stones/stacks can be contiguous or separated. MATERIAL In order to play Callanish you need: - A board with 9 squares each way, giving 81 squares in all. The outermost squares differ in colour, so players can choose to play either in a 9 x 9 (standard size) or in a 7 x 7 board. - A supply of black and white stones. - 16 gray stones (exclusively used to modify the board design).