A wide range of studies have generally found that humans appreciate certain characteristics of natural habitats, in particular the presence of other living vertebrates. This “biophilia” may reflect evolved adaptive preferences, preferences that may continue to affect our behavior today. The present study examined whether urban Europeans pay increased attention to natural stimuli even in an unnatural environment. An aquarium was installed in the window display of a Vienna, Austria, shopping mall and its effect on the responses of passers-by recorded. Assessment was by review of videotapes and quantification of duration of stay in front of the window, periods of facing the window, and such communications as pointing in the presence of others. The total number of episodes quantified was 1002 out of a total of 12,921 persons on the videotapes. As expected, all the behavioral measures of attention and exploration that were assessed indeed increased when the aquarium was present. These findings bear implications for marketing, and moreover, for ameliorating the stress that modern city environments may place on the ancient human organism.