"The true name of this coastal fort is Sindarin Aerost, which is "Fortress of the Sea" in the Common Speech. The name given on his Majesty's map ,"Eärost", is a mixed form conjoining Quenya ear "sea" and Sindarin ost, and appears to exist only in the learned imaginations of my esteemed colleagues of the Cartographers' Guild." -Findegil
Aerost was a coastal fortification in Anfalas, located on the Rathon Gondor some forty miles west of Lond Galen.Along with the neighboring fort of Lómost, ten miles further west, Aerost defended Anfalas against seaborne threats to its coast between the Celgalen and the Lefnui.Aerost was constructed in T.A.1634, in the aftermath of the Great Raid on Pelargir and served as a key link in the chain of coastal beacons used to warn the inhabitants of Corsair attacks.In T.A. 2050, Aerost was enfiefed to a local knight, whose family maintained control over the fort and its surrounding lands into the Fourth Age.