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.