Kaf
According to Arabian tradition, a great mountain that
stretches to the horizon on every side. The earth is in the middle
of this mountain, like a finger in the middle of a ring. Its
foundation is the stone Sakhrat, the least fragment of which is
capable of working untold marvels. Sakhrat, made of a single
emerald, is said to cause earthquakes. Kaf, which is frequently
referred to in Eastern tales, is said to be the habitation of genii.
To reach it one must pass through dark wildernesses, and it is
essential that the traveler be guided by a supernatural being