The following is a list showing possible treasure map grotto locations in Dragon Quest IX. For the over 10,000 treasure maps, there are 150 locations on the world map for a grotto to be, a grotto location is somewhat limited by the map type but randomly chosen from possible locations. These are just a few possibilities.
For more information regarding treasure maps, see Treasure map (Dragon Quest IX).
For Chinese source with the 150 (numbered in Hex) available, see the following location [1]
For the formula on how to calculate which map you'll get, visit [2]