The Ivory Tower

"...in that country there live a great many elephants. They follow paths worn into the stone by unreckonable generations, and by these ways they come to a place called memorial, where the bones of their ancestors lay. It is a holy place to these animals, and the ritual is performed by them every year at the end of summer.
The people in that country have taken up the bones and built from them a high place.  They surely have been building this memorial for many, many years; for at the foundation can be found the yellowed tusks and cracked femurs of mastodons. On all these bones are carved the names of the dead, and their deeds, and all that they would record.  On the oldest bones these markings are barely discernible from the natural cracks in the bone, and indeed it is said that the first writing in that part of the world came from wise men who sought to divine the interpretation of these cracks.
 As one climbs the spiral staircases of that place, the story of all the people from the very first can be read from the walls, the oldest at the foundation, and the most recent in the tusks that form the delicate arches of the roof.
Before the tower lies a deep quarry, from which is hewn layers of fossiliferous stone, and into which a mighty cataract pours.  It is this stone that is used by all the people in the building of their homes, to keep them safe against the occasional storm and flood.

Those who study in that place are said to become able to hold it entirely within their minds, for it acts as a template on the memory.  They become able to close their eyes and walk about it at will in their imagination, and read wisdom from the inscriptions on the walls. Thus dreamers are said to enter by the gate of ivory (ἐλέφας) and of horn (κέρας)."