A solitaire puzzle in which two large stones represent ships in the harbor and the smaller stones represent buoys or barriers of some manner. Your goal is to swap the positions of the two large stones, with the smaller stones determining the possible movement of the large ones -- movement that will in turn affect the location of those smaller stones.

Sia Sola includes 32 starting cards showing the position of all the stones as well as the minimum number of moves required to complete the puzzle.

Description written by W. Eric Martin and used with permission of BoardgameNews.com