For Whom the Bell Tolls is set in Spain in the 1930s, during the Spanish Civil War. Specific place settings include the Sierra de Guadarrama Mountains, Segovia, and Madrid, Spain.
Throughout the novel, one particular place setting predominates: that of the natural environment. Whenever Jordan is anxious, or stressed, or simply meditative, he turns to the nature around him as a means of disassociating from the horrors of violent conflict. In a way, nature is its own character in the novel, heralding shifts in mood and tone in its role as place setting. Note, for instance, how Jordan's mind fixes on the natural environment as he comes face to face with death:
Robert Jordan saw them there on the slope, close to him now, and below he saw the road and the bridge and the long lines of vehicles below it. He was completely integrated now and he took a good long look at everything. Then he looked up at the sky. There were big white clouds in it. He touched the palm of his hand against the pine needles where he lay and he touched the bark of the pine trunk that he lay behind.
In the above excerpt from Chapter 43, Jordan uses nature to tether himself to the present moment, despite death and pain encouraging him to retreat inside himself. The feeling of pine needles under his hands grounds him, tying him to the present moment.