Captured German trenches, Somme sector, July 1916. The German defenses are not very clear in this photo, but the barbed wire is clearly well cut, and the ground is not badly churned by shellfire. From the white chalk showing on the ground, the German trench seems to be dug along the military crest in full sight of the British lines. This sort of forward-slope position (and the gentle slope involved here) were both typical of the Somme sector, and offered the best possible conditions for British artillery weapons and doctrine of the period.
Source: IWM photo Q93.