The outermost ring within Moscow is the Moscow Ring Road (often called ''MKAD'', acronym word for Russian ''Московская Кольцевая Автомобильная Дорога''), which forms the cultural boundary of the city, was established in the 1950s. It is to note the method of building the road (usage of ground elevation instead of concrete columns throughout the whole way) formed a wall-like barrier that obstacles building roads under the MKAD highway itself).