Arcanum was a city on Amargosa‘s inhabited continent. Situated on the eastern coast, it handled a large percentage of the planet’s food processing. It was destroyed in a fusion blast during the Gelt Incursion.
While a colony ship parked over the city about a week after the invasion, a Marine contingent holed up in the foothills near the ruins. They regularly communicated with the Founders' Mine. The Gelt garrisoned the immediate vicinity while a contingent of Marines under command of Major Hu, formed a resistance in the surrounding hills.