Special Warfare Center
From Halopedia, the Halo wiki
The Special Warfare Center (or S.W.C.) in Songnam, South Korea, is a testing ground and training facility for the United Nations Space Command. It is located in the Kyonggi Province, and located near the South Korean capital, Seoul.
MJOLNIR Testing
The S.W.C. is one of the main MJOLNIR Battle Armor testing facilities on Earth. There is has a desert-like area with buildings and captured Covenant vehicles to give the training area a more realistic appearance.