Smoke rises after an explosion at an unidentified location, during strikes carried out Sunday against Iran, according to U.S. Central Command. (Photo: U.S. Central Command/Reuters)
Israeli intelligence services believe that Iran has transferred thousands of centrifuges intended for uranium enrichment into tunnels dug under Mount Pickaxe, according to a report by the Wall Street Journal (WSJ). This may explain the threats against the site issued on July 13 by U.S. President Donald Trump. Tehran is said to have carried out the transfer after the twelve-day war in June 2025, during which Israel and the United States struck Iran’s three main nuclear sites: Natanz, Fordo, and Isfahan.
Israeli and U.S. officials speaking anonymously to the WSJ said intelligence services shared with the United States their information that these centrifuges were moved “deeply into tunnels” under the mountain.
Underground complex
This information was passed along as, according to an Israeli military official, Tel Aviv considers that the U.S. airstrikes did not sufficiently focus on infrastructure related to Iran’s nuclear capabilities and that “there are still things to be done,” particularly concerning Pickaxe.
Rising to around 1,600 meters above sea level, the Mount Pickaxe site, or “Pickaxe Mountain,” houses a vast underground complex that could host nuclear facilities linked to the Natanz complex, located about 250 km south of Tehran. In an interview with Hugh Hewitt on Salem News, Trump had threatened to strike this highly secured Iranian facility. These threats came as clashes resumed despite the signing of a memorandum of understanding intended to end the conflict between Tehran and Washington and pave the way for lasting peace.
Long kept secret, known in Iran as Mount Kolang, the underground Pickaxe complex has been monitored for several years by Israel and the United States. Dug to an estimated depth of 90 to 140 meters under the rock, it is reportedly large enough to house several facilities linked to the Iranian nuclear program. According to media outlet The War Zone, two separate tunnel networks are located under Mount Pickaxe. The first is thought to have been built around 2007, while construction of the second reportedly began around 2020. The entire complex, within a vast security perimeter, is located immediately southwest of the Iranian nuclear site at Natanz.
Protection of equipment rescued after the 2025 strikes
Israeli and U.S. officials fear that Tehran may use the site to store or manufacture nuclear material, or even set up an enrichment facility there. However, the possible presence of centrifuges is not enough to prove such a facility is under construction: according to the WSJ, Iran may simply have moved surviving equipment from the June 2025 strikes there to protect it. According to The Institute for Science and International Security (ISIS), work has continued there over the past fifteen months, including tunnel reinforcement, regular truck movements, and the creation of a security perimeter. In this context, David Albright, head of ISIS, believes it is “plausible” that Iran has transferred centrifuges there. The think tank says satellite images show that Iran has already begun to block access, at least partially, to this new facility since the start of Israeli and U.S. airstrikes. Even before the conflict, Iranians were also seen burying and reinforcing the entrances to the tunnel network built in 2007.
The International Atomic Energy Agency (IAEA) said on June 23, 2026, that Iran still refuses to grant its inspectors access to the site and has provided no specific information about the activities underway there. Its director general, Rafael Grossi, recalled that Tehran had already announced its intention to conduct nuclear activities there as early as 2021.
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