From Tar Valon Library
During the Breaking, while the Ogier were displaced from the stedding, they learned to work stone, to mould it so that it seemed almost alive (TEotW, Ch. 36). As civilisation re-established itself, they were responsible for building many of the great cities that arose during the time of the Compact of the Ten Nations. As these were far from the few stedding that had been found, the Ogier planted trees and plants, in groves to remind themsleves of the trees they had left behind (TEotW, Ch. 44). When the male Aes Sedai left the sanctuary granted them, and gave them the ability to grow the Ways, they grew waygates to each of the groves.
Most of them are long gone, few of the great cities remain in any form and of those that do, the groves in Caemlyn and Tear long gone (TEotW, Ch. 44) and the grove in Cairhien abandoned (TEotW, Ch. 26) and then cut down when Barthanes took the land and built his manor there (TEotW, Ch. 23). Illian and Tar Valon may be the only groves remaining (TEotW, Ch. 26).
"Mostly they used the trees of the land and the place. You cannot make the land go against itself. Not for long; the land will rebel. You must shape the vision to the land, not the land to the vision. In every grove was planted every tree that would grow and thrive in that place, each balanced against the next, each placed to complement the others, for the best growing, of course, but also so that the balance would sing in the eye and the heart. Ah, the books spoke of groves to make Elders weep and laugh at the same time, groves to remain green in memory forever." (Loial, The Eye of the World, Chapter 36)