IntroductionThere is plenty of evidence to suggest that people recover more quickly from stress and mental fatigue in natural then in urban environments (e.g. Berto et al., 2005; Hartig et al., 2003; Ulrich et al., 1991). But, we know little about the environmental features that aid restoration. Environmental Restoration Theory (Kaplan and Kaplan, 1989) suggests that non-threatening natural environments help people rest their mental fatigue because they attract attention involuntarily. Environments which are difficult to negotiate or may harbour a threat are not likely to be restorative, as they require directed attention to deal with such threats or challenges. In reality most natural environments are full of factors that demand directed attention (e.g., to prevent tripping). We studied actual and perceived restorative in natural environments which score high or low in prospect and refuge. Prospect-refuge theory suggests that humans prefer environments high in prospect (a wide field of vision) and refuge (places to shelter), because they afford survival (Appleton, 1975). Prospect and refuge affects preferences and fear ratings for both natural and urban environments (e.g., Andrews and Gatersleben, 2010; Fisher and Nasar, 1992), but we know little about the restorative potential of such environments. Environments which provide little shelter or no field of vision are expected to be less restorative as they required directed attention to deal with potential threats.StudiesIn an on-line study people (n = 198) were exposed to slides of natural environments scoring low, moderate or high in prospect-refuge. As expected, environments high in prospect-refuge were perceived as more restorative and less threatening. But findings varied for perceived physical and social threats. In a lab and field experiment 17 participants made a walk through both a real and a similated environment low or high in prospect-refuge. In both the field and the lab experiment respondents recovered more quickly from mental fatigue and negative mood in environments high in prospect-refuge than in environments low in prospect-refuge. Significant results were found for physiological measures as well as self-reports. Fear arousal increased during exposure to environments high in prospect-refuge but actually increased in environments low in prospect refuge. ImplicationsThe findings of the research have implications for the planning and design of natural environments such as country parks which many people visit because of their restorative potential (a place to get away and relax). Such benefits may not be achieved if a visit requires directed attention and if the environment is perceived to harbour physical and social threats. Creating open environments with high levels of prospect and refuge are more likely to be restorative.