Two experiments address in more detail the finding that mental fatigue changes the relative preferences for natural over urban environments. Two propositions underlie this set of experiments. The first proposition is that in earlier research the initial differences in preference between natural and urban environments, i.e., for participants not yet attentionally fatigued, may have influenced the shift in preference from more urban to more natural scenes after a fatigue induction. To remedy this we selected a series of urban scenes that were rated as beautiful as a series of natural scenes to put this central hypothesis of ART to a more rigorous test. We additionally hypothesized that part of the beauty of the urban scenes was due to the presence of natural elements in these scenes. The second proposition is that not only mental effort, but also physical effort may weaken self-regulatory ability, of which the ability to focus attention is one manifestation. Therefore extreme physical effort may induce the same shift in preference for natural over urban scenes as mental fatigue may do. In the first experiment the set of 20 natural and urban scenes, matched on beauty, were rated before and after a task used to induce attention fatigue, by a group of adolescents in a between-subjects design. We applied both subjective ratings and physical measurements of naturalness of the scenes to control for effects of nature in urban settings. In the second experiment, professional cyclists rated the selected natural and urban scenes before and after an extremely demanding physical exercise test followed by a recognition task. Ratings were separated by two weeks, to avoid memory effects. The cyclists’ preference ratings were again used to test the hypothesis that preference for urban scenes would decrease relative to preference for natural scenes after expending the willpower needed to achieve this maximal effort. We again controlled for natural elements in the urban scenes. Results