Beneath a ruined mosque on a Kenyan island, archaeologists found seventeen layers of earlier buildings.
This is Shanga, on Pate Island, in the Lamu archipelago off the northern coast of Kenya. It was a town of the Swahili coast, and today it lies in ruins.
The site was first studied by James Kirkman in the 1950s and excavated again in the 1980s by Mark Horton, who opened ten trenches over about eight years.
Under the Friday Mosque, Horton’s team found seventeen phases of building. A burnt tree stump from the earliest levels gave a radiocarbon date between 703 and 848, which does not by itself prove that a mosque stood there. The Friday Mosque itself is dated to the eleventh century.
Two more mosques, the Eastern and the Western, were added in the late thirteenth and fourteenth centuries.
The town had about 185 stone houses and around five hundred tombs. Excavators also found sixty-four silver coins with Arabic inscriptions, dated to roughly 800 to 1100.
The town was deserted in the early fifteenth century, and the cause is unclear. One idea is a failing water supply. People called the Washanga, who live in nearby Siyu, are said to be descendants.
A legend in the Pate Chronicles dates the town to about the year 600, which archaeology has not confirmed. Sources differ on when the first mosque was built here.