These conditions caused some soldiers to develop a problem called trench foot. There were many lines of German trenches ... in the trenches during World War One. WW1 SOLDIER JACK: Mud?

In honor of Veterans Day and the 100th anniversary of the end of World War I ... patiently in a trench as they anticipate a German attack. National Geographic Nearby, on one of the tunnel walls ...

World War I remains ... of young German soldiers who are swept up in patriotic fervor to serve on one of history's grand battlefields, only to experience the mundane savagery of trench warfare.