(A) Permanent monuments shall be of concrete four inches by four inches by 30 inches, with a half-inch iron pin cast in the center, set in such a manner that they will not be moved by frost and shall be placed in the field as required by the Illinois Compiled Statutes.
(B) All lot corners shall be marked by one-half inch iron pins not less than 30 inches in length and driven into the ground and shall not protrude above the ground surface more than one and one-half inches.
(C) These monuments must be placed at all corners, at the end of all curves, at the point where a curve changes its radius, at all angle points along a meander line, the points to be not less than 20 feet back from the normal water elevation of a lake or from the bank of a stream, except that when the corners or points fall within a street or proposed future street, the monuments must be placed in the right-of-way line of the street. All internal boundaries, corners and points must be monumented in the field by like monuments as defined above.
(1994 Code, § 34-3-5)