Cape Delgado (Portuguese: Cabo Delgado) is the northernmost point of Mozambique, a coastal promontory on its border with Tanzania. It is the arc-shaped delta of the Rovuma River and was created from sediment deposited by the Rovuma as it empties into the Indian Ocean. It is sometimes identified with Prasum, the southernmost point of Africa known to the Roman geographers Marinus of Tyre and Ptolemy. In Ptolemy's Geography, it marked the point where Africa turned eastward along a great unknown shore to meet southeast Asia and enclose the Indian Ocean.