The city stands at the head of a small valley, 11,380 ft.
The city is built on rolling ground about 900 ft.
From Mafu to the sea, a distance of 215 m., the Senegal is navigable all the year round by vessels drawing not more than to ft.
It is a lonely lake, situated in extremely wild surroundings at a height of 1153 ft.
The mean depth is 189 ft., and the maximum 512 ft.