Ключевые слова: abandoned, airport, area, area51, asphalt, background, barbed, barbwire, border, boundary, business, camp, captivity, closed, company, cordon, crime, danger, dangerous, escape, fence, forbidden, freedom, frontier, gate, highway, horizon, land, metal, military, no, prison, private, property, protection, restricted, safety, security, sharp, sign, sky, system, travel, trespassing, wall, war, warning, wire,