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Satellite images reveal Iran fortifying nuclear facility tunnels
New satellite imagery analyzed by experts shows Iran is strengthening tunnel entrances near its nuclear sites, including a complex adjacent to the Natanz facility. The activity coincides with stalled negotiations between Tehran and Washington, as US officials warn of potential military action if a new nuclear agreement isn't reached.
Construction activity at Pickaxe Mountain
Recent photographs of Mount Kolang Gaz-commonly referred to as Pickaxe Mountain-reveal fresh concrete being poured at tunnel entrances, according to the Institute for Science and International Security (ISIS), a US-based research group. A concrete boom pump was visible at the site on February 10, alongside newly flattened earth and a reinforced structure near another entrance.
Analysts suggest the upgrades are designed to shield the facility from potential airstrikes. While Iran claims its nuclear program is purely civilian, the size and location of the complex have raised concerns about possible uranium enrichment activities. ISIS noted that heavy machinery and construction materials indicate the site is not yet operational.
Repairs and defenses at other nuclear sites
Satellite images also show defensive enhancements at two other key locations: the Natanz nuclear facility and the Isfahan nuclear complex, approximately 125 kilometers to the north. At Isfahan, tunnel entrances have been sealed with earth, a tactic ISIS says would mitigate damage from airstrikes or ground assaults targeting stored nuclear material.
At Natanz, a new roof was constructed over a damaged anti-drone cage between December and January. ISIS assessed the structure was added to obstruct surveillance of activities beneath it. The site was among those targeted in joint US-Israeli airstrikes in June 2025, which President Donald Trump claimed had "obliterated" Iran's uranium enrichment capacity.
Iran's nuclear program remains intact, experts say
Despite last year's strikes, analysts argue Iran retains the knowledge and infrastructure to rebuild its nuclear capabilities. Prof. Sina Azodi of George Washington University stated Iran is "operating under the assumption that attacks will recur" and is prioritizing the protection of its facilities.
"The Iranian nuclear program hasn't been destroyed. Once you have the technology and capacity, you can always reconstruct it."
Prof. Sina Azodi, George Washington University
Diplomatic efforts continue amid urgency
Rafael Grossi, director general of the International Atomic Energy Agency (IAEA), told the BBC that a new nuclear deal between Iran and the US is possible but warned that the opportunity could close abruptly. He emphasized the need to act quickly, noting that Iran's stockpile of 400 kilograms of highly enriched uranium-just a technical step away from weapons-grade material-remains stored in underground bunkers targeted in last year's strikes.
Tensions escalated in June 2025 when Trump ordered strikes on three Iranian nuclear sites after claiming Tehran was within a month of developing a nuclear weapon. While Pickaxe Mountain was not hit, Natanz suffered significant damage.
