The Tomb of Askia is the most important sight in Gao and one of the great monuments of West Africa. This 15-metre adobe pyramid, built around 1495, is the burial place of Askia Muhammad I, the greatest ruler of the Songhai Empire. In 2004 it was designated a UNESCO World Heritage Site — the only such site in Mali outside of Timbuktu and Djenné.
The pyramid is a masterpiece of Sudano-Sahelian architecture — built entirely from mud brick and reinforced with wooden beams that project outward from the walls in a distinctive hedgehog pattern. These projecting timbers serve a structural purpose (they act as scaffolding for annual replastering) and have become the defining visual motif of the style. The tomb is surrounded by a mosque, a marketplace, and the old cemetery of the Songhai kings. A small museum at the site provides context on the Songhai Empire's history.