Tar Valon

From Wotpedia

An island city in the River Erinin, within sight of the Dragonmount, and center of Aes Sedai power. "The Wheel of Time turns around Tar Valon, and Tar Valon turns around the Tower." Kings and Queens bow before the power that Tar Valon holds.

Tar Valon is the home of the White Tower, where the Aes Sedai reside and train. The Tower, and much of the city, was built by the Ogier. Tar Valon is a city-state of sorts, over which the Amyrlin Seat rules. The "Shining Walls" of Tar Valon are thought to be impregnable (never mind the difficulty in taking a city filled with Aes Sedai), and the common belief is that no army has ever breached them. In fact, this last is Aes Sedai deception, as in the Trolloc Wars the armies of the Shadow actually managed to breach the Tower, and burn part of it and also at least 2 of the False Dragons armies reached the Tower to rescue them.