The real-world island of Kiska (on which the in-game island of Skira is directly based) is located on the western end of the Aleutian Islands, Alaska and was involved in WWII. It was at one point liberated by the United States Army and the Canadian Armed Forces after capture by Japanese forces. The developers have aimed to copy the 277.698 km (107.220 sq mi) accurately to give players a sandbox composed of natural terrain, instead of artificially designed or procedurally generated terrain.
Skira is a volcanic island with a variety of terrain. At one end is a stratovolcano, 8.5 by 6.4 km (5.3 by 4.0 mi) in diameter at its base and 1,221 m (4,010 ft) high, and at the base of the volcano is a section of low lake lands. A ridge of 1,000+ foot mountains runs down one side of the western portion of the island while the other side is generally flatter with numerous lakes and small waterways.
In real time, crossing the island would take 9 hours on foot, 4 hours in a jeep and 20 minutes in a helicopter. However, it is only possible to do this within the PC mission editor or with the Skira Island Tour mission. Skira is sparsely populated with some towns and more isolated houses and settlements. An interview with developers suggests that the civilians have all been evacuated ahead of the arrival of US forces, however, non-military corpses can still be found in several areas.