Monuments shall be a size and shape required by Section 4, Chapter 358 of the Laws of 1963, and shall be placed in accordance with said statute. In addition to the required monuments, after the grading is finished, the developer shall install a steel stake one inch in diameter and 30 inches in length on lot corners, lot line angle points, or other changes in direction not marked by monuments, and at all angle points or discontinuities in easement lines where such easements are not parallel to property lines.