The Gilgel Abay, or Lesser Abay, is a river of central Ethiopia. Rising in the mountains of Gojjam, it flows northward to empty into south-western Lake Tana in a bird's-foot delta. Tributaries of the Gilgel Abbay include the Ashar, Jamma, Kelti and the Koger. It was regarded as the true source of the Nile for a long time and the Jesuit priest Pedro Paez visited it in 1618. The name Gilgel Abbay means Lesser Nile, as Abbay is the name for the Blue Nile.