"There is a Mountain situated in the midst of the earth or center of the world, which is both small and great. It is soft, also above measure hard and stony. It is far off and near at hand, but by the providence of God invisible. In it are hidden the most ample treasures, which the world is not able to value. This mountain - by envy of the devil, who always opposes the glory of God and the happiness of man - is compassed about with very cruel beasts and ravening birds - which make the way thither both difficult and dangerous. And therefore until now - because the time is not yet come - the way thither could not be sought after nor found out. But now at last the way is to be found by those that are worthy - but nonetheless by every man's self-labor and endeavors.
To this Mountain you shall go in a certain night - when it comes - most long and most dark, and see that you prepare yourselves by prayer. Insist upon the way that leads to the Mountain, but ask not of any man where the way lies. Only follow your Guide, who will offer himself to you and will meet you in the way. But you are not to know him. This Guide will bring you to the Mountain at midnight, when all things are silent and dark." (Thomas Vaughn, Lumen de Lumine, or a New Magical Light ).
And the seventh mountain was in the midst of these, and it excelled them in height, resembling the seat of a throne. (Book of Enoch, chapter XXIV)