No exterior fences, walls, hedges or accessory buildings or structures may be erected, placed, or altered on any lot which extends beyond the front of the dwelling erected thereon toward the street on which the lot is situated until the plans and specifications showing the construction and location of such wall, fences or hedges are submitted to the Architectural Control Committee and approved as to design, materials, and height. All fences shall be of ornamental iron, masonry, rock or wood construction. No chain-link fences shall be permitted, except to enclose swimming pools and only if they are not visible from any street.