DEMBEA, a very extensive lake, situated in the heart of Abyssinia, and supposed to be about 450 miles in circumference. It contains many islands, one of which is of considerable size, and is made a place of confinement for state prisoners. The numerous streams which descend from the mountains of Damot and Gojam flow into this lake. The Bahr-el-Azrek, the great river of Abyssinia, and often supposed to be the real Nile, falls into this lake on the west, and issues out again on the south-east; and it is remarked, that the stream may be distinguished through the whole of its passage across this immense body of water.