Ishido is a puzzle board game consisting of a set of 72 stones and a game board of 96 squares.
Every stone has two attributes: a color and a symbol. There are six colors and six symbols in each stone set, thus creating 36 unique stones. Since each stone comes in a pair, there are therefore 72 stones in each stone set.
The primary objective of Ishido is to place all 72 stones onto the board of 96 squares. The challenge arises because stones must be placed adjacent to others that they match, either by color or symbol. When the board begins to fill up, this objective is not so easily accomplished.
A valuable move is the 4-way, in which a stone is placed in the midst of four others, two of which are matched by color, and two which are matched by symbol.
Ishido comes with 6 differently themed stone sets, 5 different game boards, and a variety of Oriental chimes and sound effects.
Source: Wikipedia, "Ishido: The Way of Stones", available under the CC-BY-SA License.