Rena Tower
From Tar Valon Library
Rena tower is one of the Borderland towers. It was one of the northernmost towers and since the Blight spread further south had laid within it, though due to its formidable defences was generally considered safe from Shadowspawn. It was commanded by Niach Otakamo and was thought to have fallen to a Trolloc attack after sending a warning flash then giving no further response.
(Reference Towers of Midnight, Prologue)