Minted in 1968 for the 19th Olympic Games in Mexico City, the reverse shows a 16th-Century Aztec ball player, striking a hard rubber ball with his right hand, which seems odd because it is generally recognized that only the buttocks and hips were permitted in moving the ball along. Still, this is a classic engraving of the player, and on the obverse, of the national coat of arms.  

An important historical coin.