I'm just doing a re - read of TDR and at the part where egwene goes through the arches to become Accepted. Aes Sedai dont seem to know what it was used for in the AOL, what do you think it may have been used for by aes sedai back then?, i think it may have just served almost the same purpose

I think it was used as a portal

personally, i think it was a virtual reality simulator(either for work or play) OR it was used for psychological treatment(having your fears and such 'brought to the surface'). i'm leaning more to the latter.

Or infact...it could have been used to test Novices to see if they were ready to be accepted ;-) I think that would magnificently ironic and wonderful.

I am not sure if the Age of Legends had Novice or Accepted since Aes Sedia were organized differently then and since becoming Aes Sedia was not based on strength then.  I am not sure either about there being 3 levels (with Aes Sedia being highest) in the Age of Legends; because of the same reasons.

 

About the ter'angreal, there might have been a chance that it was not used for anything.

 

This page tells some about it::

http://encyclopaedia-wot.org:8008/items/three_arches.html

 

This isn't what the OP had in mind but I have another "Rings"-related question.

 

 

Do you think the Rings in Rhuidean create an effect like the one Rand endured when he traveled to Toman Head using the portal stone in tGH? I know Moiraine saw multiple possibilities for her life.