From PathfinderWiki

Arvensoar is the tower built by local Varisians and the citizens of Magnimar to replace the Seacleft Spire after it was destroyed by an angelic being. It took over 18 years to create the tower, but it now stands as a symbol of the city's receptiveness to the guidance of good spirits.1

At approximately 400 feet in height, the tower is the tallest structure in Magnimar and stands over the districts of Lowcleft and Naos. The tower serves as the barracks and fortress for the local city watch and is defended with eight powerful trebuchets able to target any attackers regardless of the direction from which they attack.23