Garternay (said to mean 'Root of the Great Tree' in D'ni language) was the old and possibly original home Age of the people called the Ronay. The meaning of its name as "root" of the Great Tree of Possibilities suggests that it was not written by a Writer, but was the origin of the Art, with all links to other Ages, including the Age of D'ni, stemming from it.
Garternay was an ancient world that was orbiting a Red giant star. Nothing is known about the geography or landmarks of Garternay other than the King's Arch, through which it was prophesied the Great King would come to guide the Ronay.
It was known to the Ronay that their world was doomed by its aging sun, and would relatively soon no longer be able to sustain life. Fortunately, they had developed the Art: a way to write special Books which provide a Link to another Age. Several Ages were written to house the Ronay exiles, with the majority Linking to Terahnee, an immense and fertile world. A conservative minority, led by the Writer Ri'neref, instead decided to leave the host of the Ronay, as they felt that the Ronay had become too arrogant and had forgotten their humility. This splinter faction instead linked to the Age of D'ni, an Age written by Ri'neref. There they formed the D'ni empire, in a massive cavern deep beneath the surface of the Age.
Garternay had been uninhabitable and obviously the D'ni people monitored its condition after the exodus. it is believed to have been destroyed by natural forces and on that day, Leetar 21 3646, the event was celebrated on the First Day of Dancing.
Officially, no Linking Books to Garternay have been found. However, Garternay was listed as an Age under preparation by the D'ni Restoration Council, suggesting at least one Linking Book had been found.