Seshrentor

Seshrentor was a tower standing in the Graypeaks of the Savage Frontier.

History
It was once the home of a powerful lich, until it was destroyed with the help of Simov the Pious. Seeking isolation because of his power to know all things around him, the priest of Oghma then moved into the tower. It became his scriptorium, where he collected and copied books that Khelben Arunsun brought him.

Defenses
Thanks to a wish, Simov knew everything that happened around him (and thus the tower) in a one-mile (1.6 kilometer) radius, including the movements of all people and even their thoughts.