Others, such as Koshien Stadium in Hyōgo Prefecture, Japan, have an infield of entirely dirt. Some ballparks have grass or artificial turf between the bases, and dirt only around the bases and pitcher's mound. The space between the bases and home is normally a grass surface, save for the dirt mound in the center. The infield is a rigidly structured diamond of dirt and grass containing the three bases, home plate, and the pitcher's mound. A baseball field can be referred to as a diamond.
