This paper presents an astronomical study of a sample of ancient cairns, stelae and burials at the cairnfield of Xiis (Heis) in Somaliland, a historic centre of long-distance trade between different cultures. The analyses reveal a set of significant orientations that the paper relates to the seasonal movements of the region’s nomads, which are believed to have remained unchanged for millennia. The structures, which date from the first to the third century AD, are also contextualised within the broader astronomical traditions of the Somali and other Cushitic peoples, many aspects of which predate the arrival of Islam to the Horn of Africa and constitute some of the most distinctive and complex aspects of Somali culture.

The research of the Incipit Archaeological Project in Somaliland has been funded by MCIN/AEI/10.13039/501100011033 (Grants HAR2013-48495-C2-1-P and PGC2018-099932-B-100), provided by “ERDF: A Way of Making Europe” and by the Palarq Foundation. The research presented in this paper was also funded by the European Union through the European Union Research and Innovation Framework Programme, Horizon 2020, through the Euro-pean Research Council (ERC StG 853390-StateHorn). ACGG also acknowledges support from grants PID2020-115940GB-C22 ’Orientatio ad Sidera V’ and project EIN2020-112463, funded by MCIN/AEI/10.13039/501100022033 and by the European Union “NextGenerationEU”/PRTR”