Recent years have seen increasing interest in the experience of prehistoric monuments. This article explores the possibility that the construction and experience of early Neolithic chambered cairns in South Wales was grounded in principles of asymmetry and sidedness. This was reflected in their landscape setting, architecture, and was actively drawn on through time in patterns of structured deposition. Ultimately, we conclude that the differences between symmetry and asymmetry may have played an integral role in the conception of place in the British Neolithic.