Permanent concrete monuments shall be accurately set and established at the intersections of all outside boundary lines of the subdivision; at the intersections of those boundary lines with all street lines; at the beginning and end of all curves; at points on curves where the radius or directions changes; and at such other points as necessary to establish definitely all lines of the plat. Concrete monuments shall be at least thirty-six inches long and at least six inches in diameter, and shall be provided with an appropriate center point. Solid steel pins 5/8" X 30" or iron pipe monuments at least one inch in diameter and at least thirty inches long may be used at all other points including lot-corners. (Ord. 9-1993. Passed 7-12-93.)