Monuments. Monuments shall be placed at all block
corners, angle points of curvature in streets and points of tangency
on horizontal curves and at intermediate points as shall be required
by the Planning Board and by the advice of a licensed professional
engineer or licensed land surveyor; however, in no case shall there
be fewer than four permanent monuments per block. The monuments shall
be of such material, size and length as may be approved by the Planning
Board by the advice of a licensed professional engineer or licensed
land surveyor.