The fortifications were built between 1935 and 1938 as a part of the country deffense system. It consits of chains of forts and fortresses in the border regions and on selected inland links. The reason being deffence againts enemy countries of Germany, Austria, Hungary and Poland. It consits of light and heavy forts and artillery forts. After acceptation of the Munchen Treaty most of the system was in the hands of the enemy. Today many of the objects are restored to the original condition and opened to public.