The cognitive mechanisms that underlie beliefs in the supernatural are not well understood. In an attempt to understand this phenomenon, we hypothesized that the cave environment “affords” such usage. In our experiment, 52 participants completed a survey about their metaphysical beliefs inside a room providing a great deal of natural light, while another 52 participants completed the same survey in a dark and windowless room. The survey asked participants to rate their beliefs in a variety of supernatural phenomena and also included multiple-choice questions which described bizarre scenarios that could be explained either scientifically or supernaturally. The supernatural responses to both the rating-scale questions and to the multiple-choice questions were significantly higher in the cave-like condition. These results are consistent with anthropological claims that the dark zones of caves may have played a role in the environment of evolutionary adaptedness that contributed to humans’ tendency toward magical thinking.