Underground Facility in Libya, by Edward Cooper, 1996 Underground facilities around the world such as this one in Tarhuna, Libya, pose a significant threat to the United States, and are a major concern to DIA. Defense Secretary William Perry released this depiction of Tarhuna to the public in April 1996, citing intelligence that it likely housed a chemical weapons plant. The structure, dug into a hillside, purportedly could withstand an air-strike.