Israeli intelligence indicates that Iran has moved thousands of uranium enrichment centrifuges into deep underground tunnels at a site known as Pickaxe Mountain. This relocation is believed to have occurred after a 12-day conflict in June 2025, during which U.S. and Israeli airstrikes targeted Iran's primary nuclear facilities. The intelligence assessment, which Israel shared with the United States, suggests these centrifuges might be reserve machines previously stored at Iran's main nuclear sites, or possibly components from facilities damaged in the conflict.
Experts estimate the Pickaxe Mountain complex extends 90 to 137 meters (295 to 450 feet) beneath solid rock and is large enough to house multiple nuclear-related operations. Construction at the site reportedly began in 2020 after an explosion at the Natanz facility, an event Iran attributed to sabotage. The International Atomic Energy Agency (IAEA) has not been granted access to Pickaxe Mountain, and Iran has not provided information regarding activities or future plans there, despite having informed the IAEA in 2021 of its intention to conduct "nuclear activities" at the site.
Analysts caution that while the relocation of centrifuges is concerning, it doesn't definitively confirm the establishment of an enrichment facility. Iran might have moved the surviving centrifuges to protect them from future attacks. However, Nate Swanson, a former U.S. National Security Council member, highlighted that Iran's history of covert nuclear activity makes any undeclared work at such a hardened underground site particularly troubling, emphasizing the need for IAEA inspection. The site, located 220 km (140 miles) south of Tehran and 2 km (1.2 miles) from the Natanz nuclear complex, was not targeted in the 2025 conflict or the subsequent military operations, leading some to believe it was not considered to hold "sufficient value.
The Pickaxe Mountain facility is believed to be beyond the reach of most powerful bunker-buster bombs, making it a highly protected location. The Institute for Science and International Security (ISIS) stated in a report that while the facility is likely not yet operational and construction continues, if Iran resumes centrifuge manufacturing, it could install a smaller assembly facility there for a nuclear weapons program. The continued activity, including vehicle movements at the site's western entrances, suggests ongoing work inside the tunnel complex, despite a memorandum of understanding signed by the U.S. and Iran requiring a nuclear program status quo.
U.S. President Donald Trump has expressed an intent to attack Pickaxe Mountain, noting its heavily fortified nature and the lack of inspections by the International Atomic Energy Agency, which concerns global nuclear watchdog officials.
