From Tar Valon Library
In the center of Rhuidean, is a large collection of angreal, ter'angreal and perhaps even sa'angreal, taken there by the Aiel during the Breaking (TSR, Ch. 26). The plaza is dominated by Avendesora, and a series of tall, thin glass columns. These are a ter'angreal, perhaps the only one made specially for the Aiel (TSR, Ch. 25), which reveal the Aiel's history to any of Aiel blood who enters, the person experiencing key events in the lives of their ancestors (TSR, Ch. 25; Ch. 26). What is seen is different for each individual, though all see two events: the sharing of water with the ancestors of the Cairhienin, and the treaty of Rhuidean (TSR, Ch. 34). This knowledge is so terrible that most men who enter the glass columns die. Those who survive are marked with a dragon tattoo on one arm, save for Rand, who came out with a dragon tattoo on each arm (TSR, Ch. 34).
After they had walked a mile, the street suddenly ended at a great plaza, perhaps as far across as they had walked and surrounded by those palaces of marble and crystal. Startlingly, a tree stood in the huge square, a good hundred feet tall and spreading its thick, leafy limbs over a hide of dusty white paving stones, near what appeared to be concentric rings of clear, glittering glass columns, thin as needles compared to their height, nearly as much as the tree’s. (TSR, Ch. 24).