|Locations of interest|
|First appearance||Uru: Ages Beyond Myst|
The Age of Gahreesen was created by the D'ni in the year 8500 D.E. (D'ni Era), to be used as the "Home Age" for the Guild of Maintainers, a highly secretive group, of which the construction of the buildings within the Age reflect. The buildings were designed to constantly rotate, so that writing a Linking Book from the Age would be impossible; one needs a stationary position within an Age to write a Linking Book.
The huge buildings were used as the training center for the Guild of Maintainers, evidence of that fact being the huge "Training Wall" that one can find within the bowels of one of the buildings. The rest of the Age surrounding the Guild complex seems to be jungle, in which has been noted dangerous, carnivourous creatures.
There is also evidence pointing to the fact that the Guild was opening up certain parts of the buildings to the rest of the D'ni civilization towards the end of their fall, to dispense to the populace devices known as "KI's".
Gahreesen is often referred to as Garrison, the name it had during the Uru beta period, and which is still used for the game files.
"The laws contrived by the proud are their security and their undoing. Such laws make disobedience a virtue, and obedience a sin." - Regeltavok of Oorpah - Book 12, Entry 32, Item 134