Fort Shafter is in Honolulu CDP, City and County of Honolulu, Hawai‘i, extending up the interfluve (ridgeline) between Kalihi and Moanalua valleys, as well as onto the coastal plain (as Shafter Flats) at Māpunapuna. Fort Shafter is the headquarters of the United States Army Pacific, commanding most Army forces in the Asia-Pacific region with the exception of Korea. A portion of the area is also known as the Palm Circle Historic District and is listed on the National Register of Historic Places, and has been further designated as a U.S. National Historic Landmark. It is also known as Palm Circle or 100 Area. Palm Circle covers a secret underground command center.