The western edge of the Quango valley appears, about twenty miles off, as if it were a range of lofty mountains, and passes by the name of Tala Mungongo, "Behold the Range". In the old Portuguese map, to which I had been trusting in planning my route, it is indicated as Talla Mugongo, or "Castle of Rocks!" and the Coanza is put down as rising therefrom; but here I was assured that the Coanza had its source near Bihe, far to the southwest of this, and we should not see that river till we came near Pungo Andonga.