Location from The Stormlight Archive by Brandon Sanderson
The ancient tower city of the Knights Radiant, ten tiers tall, hidden in the mountains — rediscovered and now the coalition's headquarters, powered by the Sibling spren.
Urithiru is impossibly large. The Knights Radiant built it as their headquarters thousands of years ago, and even with the entire Alethi coalition camped inside, most of the tower remains unexplored. Ten tiers of chambers, libraries, training halls, and mechanisms that no one fully understands. The Oathgates on the ground level connect to ten cities across Roshar, making Urithiru the hub of a continental transportation network. The tower was dead when they found it — its systems shut down, its Sibling spren slumbering, its heating and plumbing nonfunctional. Navani's obsessive study of the tower's fabrials gradually unlocked its secrets, culminating in her Bondsmith bond with the Sibling that reactivated the tower's defenses. Raboniel's invasion and occupation of Urithiru nearly destroyed it permanently, corrupting the Sibling with Voidlight. The tower is now the last stronghold of the coalition — the place where humanity makes its stand against Odium's forces.
A colossal tower carved into a mountain peak, rising in ten circular tiers above the clouds. Each tier is a city unto itself — balconies, hallways, chambers, and atriums sprawling through the stone. Fabrial mechanisms line the walls. The central shaft drops through all ten levels. When the Sibling is awake, Towerlight suffuses the stone with a warm glow.
Also known as: Urithiru, the tower, the tower city