During World War 2, what defensive structure did the French attempt to utilize against the Germans in the early stages of the war?

It was called the Maginot line. The maginot line was an actual line one could see that was meant for defensive purposes. It was built in the years between 1930 and 1935 and was comprised of many defensive bunkers, walls, barbed wire, etc. The reason for this was that they wanted to slow down any possible advance that could have happened by the German forces.