In 1943, British archaeologist Thurstan Shaw drove the first excavation trench into Bosumpra's floor. What he found in just 1.5 meters of depth told a story with two chapters: a long prehistoric period defined by thousands of tiny stone tools -- geometric microliths -- and small quantities of decorated pottery, followed by a later historical period marked by iron and a different ceramic tradition. Shaw's work made Bosumpra the first site of its kind excavated in Ghana, a distinction it still holds. Three decades later, Andrew Smith returned in 1973 and 1974 with radiocarbon dating technology Shaw had lacked. Smith's dates bracketed the upper occupation between 4500 BC and AD 1400, but subsequent analysis pushed the earliest human presence back further -- to at least the mid-eleventh millennium BC.

Some of the oldest pottery in sub-Saharan West Africa comes from this cave. Stratigraphic evidence shows that by the tenth millennium BC, the people living at Bosumpra were producing solidly manufactured ceramics decorated with channeling and impressed patterns -- a technique known as peigne filete rigide. This matters because it challenges a long-held assumption in archaeology: that pottery follows agriculture. At Bosumpra, people were making and firing clay vessels thousands of years before farming reached this part of Africa. They were also producing partially polished stone celts and an array of geometric microliths, building a toolkit that persisted with remarkable continuity for millennia. The assemblage differs from contemporary sites in Central Africa, pointing to a distinct regional tradition rooted in the Kwahu Plateau itself.

What makes Bosumpra unique in Ghana is not any single artifact but the sheer length of its archaeological record. The site was occupied periodically from at least 11,000 BC through the seventeenth century AD -- the longest continuous sequence yet found in the country, spanning roughly 12,500 years. People used the same stone tool traditions across that vast stretch of time, even as the world outside the cave changed dramatically. During the Atetefo period, roughly 1200 to 1600 AD, stone tools continued alongside early evidence of metallurgy. Iron appeared but did not replace lithics; the two technologies coexisted, knowledge of both transmitted across generations. This persistence is itself remarkable -- at most archaeological sites, metal displaces stone quickly. At Bosumpra, the old ways held on. Even as the Akan peoples established their influence across the plateau in the late seventeenth century, the cave's material culture shows more continuity than disruption, suggesting that the people living here adapted to political change without abandoning their technological heritage.

Bosumpra's spiritual life did not end with the Stone Age. The cave served as a shrine to Obosom Pra, the deity of the Pra River, whose headwaters lie nearby in the Kwahu region. In Akan religion, the Pra's spirit ranked among the principal abosom of the Guan pantheon -- a god of rivers and the forces they carry. The rock shelter that had been a workshop and home for prehistoric peoples became, in its later centuries, a place of devotion. Today the cave serves as a Christian church, its sacred function transformed but unbroken. The shelter sits at roughly 613 meters above sea level, northeast of the modern town of Abetifi, covering about 240 square meters of floor space -- modest in size, enormous in what it contains.