Satellite images reveal intensified construction at “Kuh-e Kolang” as Tehran moves its nuclear program deeper underground following devastating June attacks.
The Washington Post reported on Friday, September 26, that Iran’s regime has accelerated construction at a deeply buried underground complex in southern Natanz following heavy U.S. and Israeli airstrikes in June that crippled its nuclear infrastructure.
The site, officially referred to in documents as “Kuh-e Kolang-Gozla” or “Kuh-e Kolang,” has been under development in the Zagros mountains since 2020. While Tehran initially described it as a centrifuge assembly center, experts have long questioned its true purpose. Recent satellite imagery indicates that instead of halting construction after the strikes, Iran’s regime has intensified its efforts to reinforce and expand the site.
According to the Washington Post, three significant developments have taken place since June 22: completion of much of the security perimeter around the one-square-mile compound, reinforcement of one tunnel entrance with rock and soil to withstand airstrikes, and a sharp increase in excavated debris, signaling continued tunneling activity.
Analysts believe the depth of the underground halls—estimated between 80 and 100 meter, deeper than the Fordow facility—suggests the regime may be preparing a secure location either for uranium enrichment or for storing highly enriched uranium closer to weapons-grade levels. Heavy trucks and excavation machinery visible in recent satellite images point to ongoing, large-scale construction.
Sara Burkhard of the Institute for Science and International Security (ISIS) told the Washington Post that clear evidence of continued tunneling is highly significant, highlighting Tehran’s determination to rebuild.
The June strikes, carried out by U.S. B-2 bombers and Tomahawk missiles alongside Israeli operations, reportedly destroyed or disabled all of Iran’s 22,000 centrifuges at Fordow, Natanz, and Isfahan. For the first time in 15 years, according to the Institute for Science and International Security, the regime had no identifiable path to weapons-grade uranium.
Yet U.S. intelligence has issued a more cautious assessment, acknowledging that while Fordow was likely devastated, the full extent of damage at Natanz and Isfahan remains unclear. This uncertainty has fueled speculation that Tehran is now moving sensitive operations deeper underground to shield them from future strikes.
Another critical concern is the fate of Iran regime’s stockpile of 60% enriched uranium. Before the attacks, the International Atomic Energy Agency (IAEA) reported Tehran held more than 400 kilograms at this near-weapons-grade level. Its current location is unknown. IAEA Director General Rafael Grossi has suggested some material may be buried underground, while U.S. officials believe much was destroyed under the rubble of Fordow and Isfahan. The ambiguity raises fears that Tehran could still secretly use remaining stockpiles for weaponization.
Tensions over the issue are escalating. On September 9, Tehran agreed to restore limited IAEA monitoring, but regime officials quickly cast doubt on the arrangement. Ali Larijani, regime’s Secretary of the Supreme National Security Council, warned that if sanctions return, the regime will end cooperation with the agency. He gave evasive answers when asked about Kolang, suggesting the site “may remain active or may close in the future.”
Ultimately, decisions on the regime’s nuclear trajectory lie with Supreme Leader Ali Khamenei. The White House has emphasized that any attempt to rebuild the nuclear program is under close watch, quoting a senior Trump administration official as saying the President will never allow Iran to acquire a nuclear weapon.
At the same time, the Associated Press reported that Iran is also rebuilding missile sites struck during the 12-day conflict with Israel. Together, these developments underscore a clear message: while exposed facilities have been destroyed, Tehran’s nuclear ambitions remain alive, now buried deeper in the mountains of Natanz.
