Sol-Arkalad; meaning "Tower of the Watch" in elvish, was once a stronghold of the Dark-Elves, but fell into disrepair during the Third Age.

It was rebuilt by the kingdom of Adar, and is now a stronghold of Morgoth; used only by Sorimmar’s armies. This fearsome castle was a sister fortress to Sol-Oltharë, and is located midway between Sirilath and the Crossroads of Gol-Gathad, along the Adar Road, at the junction of the Adar Road and the seldom-used road that leads west up to the lost city of Adarond. Once Sol-Arkalad guarded both roads, but with the destruction of Adarond, it is now primarily an outpost to guard north and south traffic between the cities of Sirilath and Kuldhûr.