Men of a Canadian machine-gun company huddle in shell holes at Passchendaele, November 1917. Now I really like this photo. It looks nothing more than a muddy hell hole, its hard to even see their are people in the picture! They had to stay in those holes for days on end, firing at the enemy and keeping guard. No wonder they ended up with so many horrid alignments, trench foot etc. As far as the eye can see the landscape looks the same, muddy, holes no trees, wildlife.
This photo also from Passchendaele shows the problems that the troops had. Guns wedged, stuck in mud, wooden slats trying to save it from sinking. Moving these blighters must have been a right bugger. They would use horses for this.