After seeing some startling scenes of German fortresses in the 2008 The Red Baron, I developed a curiosity about what the Hindenburg Line, the Siegfriedstellung, really looked like. So, here are a few pictures that turned up after a simple image search.
The line near Arras in 1917:
A bunker, keeping a weary watch over the landscape after everyone has forgotten:
The line, west of Wancourt, March 1917:
And an outpost bunker. The picture is part of a really stunning photo essay on Neuve-Chapelle and Richebourg, which can be found here.
And finally, this little guy, forgotten in the Bourlon Wood for years:
Oh, and before I forget, Operation Michael, the first of the German 1918 Spring offensives, began on March 21. As of April 1, it is running out of steam, and German attacks are repulsed along the line. See FirstWorldWar.com “On This Day” for these kind of updates.