Rubber wood. A sustainable source, all non-toxic materials (including paints). Very well made! I highly recommend this toy. My little boys love playing with it! It even doubles as a "cactus tree" by the wooden railroad they set up in our living room.
Boy I really wish Amazon would start listing countries of origin. How great would that be?? I don't know for sure where this particular toy was made, but I have other Plan Toys that indicate Made In Thailand.