The principal =Lakes= of Egypt are: 1. =Birkat al-Ḳurûn=, a long, narrow lake lying to the north-west of the Province of the Fayyûm, and formerly believed to be a part of the Lake Moeris described by Herodotus; 2. The =Natron Lakes=, which lie in the Natron Valley, to the north-west of Cairo; from these the Egyptians obtained salt and various forms of soda, which were used for making incense, and in embalming the dead; 3. Lake =Menzâlah=, Lake =Bûrlûs=, Lake =Edkû=, Lake =Abukîr=, now almost reclaimed, and Lake =Mareotis=; all these are in the Delta. Lake =Timsaḥ= (_i.e._, Crocodile Lake) and the Bitter Lakes, which were originally mere swamps, came into existence with the making of the Suez Canal. The =Fayyûm= which was in ancient times regarded as one of the Oases, is nothing more than a deep depression scooped out of the limestone, on which are layers of loams and marls covered over by Nile mud. The district was called by the Egyptians “Ta-she,” or “Land of the Lake”; at the present time it has an area of about 850 square miles, and is watered by a branch of the Nile called the “Baḥr Yûsuf,” which flows into it through an opening in the mountains on the west bank of the Nile. The Baḥr Yûsuf, or “River of Joseph,” is not called after the name of the patriarch Joseph, but that of some Muḥammadan ruler. It is not a canal as was once supposed, but an arm of the Nile, which, however, needs clearing out periodically. In the Fayyûm lay the large body of water to which Herodotus gave the name of =Lake Moeris=. He believed that this Lake had been constructed artificially, but modern irrigation authorities in Egypt have come to the conclusion that the mass of water which he saw and thought was a lake was merely the result of the Nile flood, or inundation, and that there never was a Lake Moeris. [Illustration: The Entrance to the Valley of the Tombs of the Kings at Thebes.]