The discipline of aesthetics is generally associated with art and the word ‘aesthetics’ is often taken to connote art that is valued as good or great. What that value is and how to assess it are central questions for aesthetic theory. Despite common usage, however, the word ‘aesthetic’ is not synonymous with ‘beauty’ and has applications far wider than to art alone. The etymology of ‘aesthetic’ emphasizes its central meaning of sense perception, and I use the word emphasizing that core meaning. However, sensory experience, and hence aesthetic experience, is not always positive, and when it is offensive, distressing, or has harmful or damaging consequences, the aesthetic leads us to the realm of the negative. In this essay I want to identify some of the conditions when aesthetic value is present but in unsatisfying, painful, perverse, or even destructive ways. I shall focus on the human environment and shows how the aesthetic fuses with the moral. We can give a name to sensory experience that has no clear positive value, the underside of beauty, so to say, and call it negative aesthetics.