Blue Nile Falls, just downstream from Lake Tana, so quite close to where the river starts. Much of the river is now diverted for hydroelectric power and what you see here is only 25% of the whole thing. Also this is after rainy season so it can get much bigger. The Blue Nile is one of two main tributaries of the Nile, the other being the White Nile, but volume wise, the Blue Nile brings the majority of the water. In fact this creates some water resource management issues between Ethiopia and the countries downstream (mainly Egypt).