From Tar Valon Library
Author: Atarah al'Norahn
Goaban was one of the twenty-four nations that arose either during or shortly after the War of the Hundred Years. It's location is pretty much unknown, though if you think about it, there are only a few places where it could have been located (assuming that it wasn't a tiny nation that was assimilated into another nation). These places are: between Arad Doman and Saldaea on the Aryth Ocean, in the Black Hills, north of the River Haevin and the Caralain Grass, north of the River Iralell (south of Cairhien) oe long the Shadow Coast.
By the year 600 NE, Goaban had faded away.
(Reference: The World of Robert Jordan's "The Wheel of Time")