Ключевые слова: abstract, backdrop, background, boundary, buildings, built, business, cane, chain, closed, danger, entrance, facility, factory, fence, focus concept, forbidden, freedom, gates, grid, guard, industrial, industry, keep out, link, manufacturing, metal, metallic, mill, milling, netting, no people, old, outdoor, private, prohibited, protection, public, refinery, safety, security, space, steel, structure, sugar, surrounding, wall, warehouse, wire, wire mesh,