Athrenar's Tower; commonly called the "Great Watchtower," is an extremely tall coastal fortress and watchtower, built in 44/4 under the reign of King Athrenar Sanborn of Ralas.
The tower was built upon a jutting circle of rocks on the southern coast of the Isle of Renthara. The base of the tower is only reachable on foot during low tide; otherwise the first several levels are completely underwater and the castle accessible only by boat and a long rope climb. The great tower was built as an early warning post against the Corsairs of Tar Vielca who had plagued the kingdom of Ralas for decades.
It is said that the 350-foot tall spire of the fortress is the tallest structure on Corwyn. This tower gave great aid to the ancient kingdom of Ralas during the War of the Corsairs, in which the Pirate-King was finally defeated. The tower still stands, although in some disrepair and is currently manned by the army of Rennsfar. The fortress is also referred to as ‘The Great Watchtower' and the 'Tower of Rennsfar’
Today, the tower is one of the most famous landmarks on Corwyn, and universally recognizable to any Ralani man, woman, or child; as well as seafarers and sailors everywhere.