The Mamming Hills were a desolate area of Unkerlant that contained mines of Cinnabar, the material which dragons needed to eat in order to breath fire. Cinnabar being thus a key munition of war, the Mamming Hills were an area of prime strategic importance.
A major component of the strategy of Algarve in its war with Unkerlant was the drive to capture the Mamming Hills, which, if successful, would have supplied Algarvian dragons with Cinnabar while denying it to Unkerlanter ones. Unkerlanter forces were aware of this, and met with Algarve's forces at Sulingen, determined to block the Algarvians from reaching the Mamming Hills. After much bloodshed, Unkerlant carried the day.
Working and living conditions at the Mamming Hills mines, where temperatures fell very low in the winter months, were atrocious. The mines were worked by slave labor, originally of Unkerlanters who had incurred the suspicion of King Swemmel's secret police, the inspectors for real or fancied plotting. In the later parts of the war, these were joined by large contingents of Algarvian and other prisoners of war.
The guards made little distinction between Unkerlanter and Algarvian prisoners, treating all prisoners badly. For their part, the prisoners felt no great animosity towards one another, despite being one-time enemies, feeling that "they had all lost the war" and that they had little to expect except a lingering death from which there would be no reprieve.
Garivald was one of the very few prisoners who ever managed to successfully escape from the Mamming Hills - his success due in considerable measure to his dormant magical powers of which he was himself almost completely unaware.
Literary Note Edit
In their wartime role as a strategic objective, the Mamming Hills stand for the oil wells of the Caucasus Mountains, which the Germans sought to capture until blocked at Stalingrad. As a harsh slave labor prison, they stand for Joseph Stalin's labor camps in Siberia.