. . . . "(bv) Structure means anything constructed, erected or placed on, under or above the waters of the park, or any object constructed, installed or placed on land to facilitate land use and development or the subdivision of land, such as buildings, sheds, single family dwellings, mobile homes, signs, tanks, fences, poles, docks, wharfs, piers, moorings, and any fixtures, appurtenances, additions and/o" .