"The Islamic Republic's decision to conduct sensitive atomic activities at an underground site that better protection against any enemy attacks could complicate diplomatic efforts to resolve the long-running row peacefully. Iran has said for months that it is preparing to move its highest-grade uranium refinement work to Fordow, a facility near the Shi'ite Muslim holy city of Qom in central Iran, from its main enrichment plant at Natanz."
 

 
http://www.newsmax.com/Newsfront/Iran-nuclear-enrichment-bunker/2012/01/08/id/423356