We describe the physical context of the Dinaledi Chamber within the Rising Star cave, South Africa, which contains the fossils of Homo naledi. Approximately 1550 specimens of hominin remains have been recovered from at least 15 individuals, representing a small portion of the total fossil content. Macro-vertebrate fossils are exclusively H. naledi, and occur within clay-rich sediments derived from in situ weathering, and exogenous clay and silt, which entered the chamber through fractures that prevented passage of coarser-grained material. The chamber was always in the dark zone, and not accessible to non-hominins. Bone taphonomy indicates that hominin individuals reached the chamber complete, with disarticulation occurring during/after deposition. Hominins accumulated over time as older laminated mudstone units and sediment along the cave floor were eroded. Preliminary evidence is consistent with deliberate body disposal in a single location, by a hominin species other than Homo sapiens, at an as-yet unknown date.DOI: http://dx.doi.org/10.7554/eLife.09561.001

The Rising Star cave system has produced abundant fossil hominin remains within the Dinaledi Chamber, representing a minimum of 15 individuals attributed to Homo naledi. Further exploration led to the discovery of hominin material, now comprising 131 hominin specimens, within a second chamber, the Lesedi Chamber. The Lesedi Chamber is far separated from the Dinaledi Chamber within the Rising Star cave system, and represents a second depositional context for hominin remains. In each of three collection areas within the Lesedi Chamber, diagnostic skeletal material allows a clear attribution to H. naledi. Both adult and immature material is present. The hominin remains represent at least three individuals based upon duplication of elements, but more individuals are likely present based upon the spatial context. The most significant specimen is the near-complete cranium of a large individual, designated LES1, with an endocranial volume of approximately 610 ml and associated postcranial remains. The Lesedi Chamber skeletal sample extends our knowledge of the morphology and variation of H. naledi, and evidence of H. naledi from both recovery localities shows a consistent pattern of differentiation from other hominin species.DOI: http://dx.doi.org/10.7554/eLife.24232.001

Field research requires careful preparation so as to protect the integrity of archaeological studies and ensure the health and wellness of our students and field crews. In this special issue, we hope to lay a foundation for securing health and wellness as elements of the ethical practice of archaeology fieldwork through discussions of common hazards and tools to prevent, prepare for, and address safety incidents in the field. Even as archaeology and other field sciences grapple with serious safety concerns such as sexual harassment and mental health, it can be tempting to view field sites as extensions of the classroom or office. But field research can be a high-risk endeavor where we are exposed to a range of hazards not typically encountered in a traditional learning or work environment. We reach across disciplinary boundaries toward outdoor leadership and backcountry medicine to introduce the concept of wilderness context to describe the remote—and not-so-remote—locations and conditions common to archaeology field research. These are places where small or unanticipated problems can quickly become serious incidents. By rethinking research sites as wilderness activity sites, we highlight how methodical preparation can help us craft more robust and ethical health and safety practices for all members of our teams.