External Maintenance. The exterior of any building shall be maintained in good repair and the parking lots, loading areas, rear entry areas, and other areas external to the building(s) shall be free from accumulations of dirt, petroleum, automotive fluids, debris, mud, rubbish, paper, trash, litter, and other such items. Any signs, markers, or any other methods used to indicate direction of traffic movement and location of parking spaces shall be maintained in a neat and legible condition. Any walls, trees, and shrubbery, as well as surfacing of the parking lot, shall be maintained in good condition throughout its use for parking purposes, and the Board of Aldermen shall have the authority to prohibit the use of the area for parking purposes unless and until proper maintenance, repair, or rehabilitation is completed.