Satellite Images Reveal Iran Blocking Access to "Jabal al-Fass" Nuclear Site Near Natanz Following Trump's Threats

Recent satellite imagery shows Iran has blocked the western tunnel entrances to its secret "Jabal al-Fass" nuclear facility near Natanz, by erecting massive earthen barriers. The Institute for Science and International Security reported Tuesday that Iran began placing these earthen barriers at the entrances in late July and early August 2026. They appeared clearly in satellite photos dated August 21, remaining until September 11. This Iranian action followed late July reports indicating Tehran transferred centrifuges to the facility after a June 2025 conflict. It also came after public threats by US President Donald Trump to target "Jabal al-Fass," one of Iran's remaining central nuclear sites previously undamaged by strikes. "Jabal al-Fass" is located approximately two kilometers south of the Natanz enrichment facility, featuring a deep tunnel system excavated within granite mountains. Iran previously claimed the complex was for installing centrifuges but has not opened it for IAEA inspection. The facility's depth and fortifications have raised concerns Tehran might use it for future uranium enrichment or other nuclear activities. Institute researchers clarified this isn't the first time; April and May images showed Tehran partially filled the eastern tunnel entrances with dirt. With western entrances now blocked, all four complex entrances appear impassable for vehicles. The Institute emphasized Iran's need to remove barriers to resume ground access, noting their persistence would significantly limit construction or underground activities.