Recent satellite imagery has revealed Iran fortifying the western tunnel entrances of the clandestine "Jabal al-Faas" facility, situated near the Natanz uranium enrichment site, by constructing massive earth barriers. These movements, initiated in late July and early August of 2023,
showed a series of earthen barricades placed at these entrances, remaining evident in satellite images captured on August 21 and through September 11. This action follows reports in late July indicating Tehran's transfer of centrifuges to the facility in the aftermath
of an incident in June 2022. The fortification also comes after public threats made by then-U.S. President Donald Trump, who suggested the United States might target "Jabal al-Faas," considered one of the remaining central sites of Iran's nuclear program that
had not been affected by previous strikes. The "Jabal al-Faas" complex is located approximately two kilometers south of the Natanz uranium enrichment facility and features a deep tunnel system excavated within a granite mountain range. Despite Iran's previous claims that this
complex is intended for centrifuge installation, it has not permitted inspections by the International Atomic Energy Agency (IAEA). The facility's depth and fortifications have raised significant concerns about the potential for Tehran to use it in the future for uranium
enrichment or other sensitive nuclear activities. Researchers at the Institute for Science and International Security note that this is not the first instance of Iran blocking access to this complex. Previous images from April and May showed that Tehran had also
partially filled the eastern tunnel entrances with earth. With the western entrances now obstructed, it appears that all four entrances to the complex are no longer accessible to vehicles. The Institute emphasizes that Iran will need to remove these earth barriers
to restore ground access to the facility. As long as the barricades remain in place, Tehran's capacity to conduct construction or any other activities within this underground complex will be severely limited.
