Iran has been fortifying an underground complex near one of its nuclear facilities, according to analysis of new satellite images. This activity comes at a time of heightened tensions as talks between Iranian and US officials continue, with President Donald Trump threatening fresh military action against Iran if it does not agree to a new deal on its nuclear program.
The photos, first analysed by the Institute for Science and International Security (ISIS), a US-based think tank, show tunnel entrances being strengthened at Mount Kolang Gaz La - also known as Pickaxe Mountain. Experts say this facility may be designed to protect Iran's uranium enrichment activities or key equipment, but its exact purpose - and whether it is operational - remains unclear.
Iran insists its nuclear program is entirely peaceful and denies it is seeking to develop nuclear weapons. However, Trump stated in June 2025 that Iran was as little as a month away from having a nuclear weapon when he ordered strikes on three underground nuclear sites where centrifuges were producing highly enriched uranium during a brief conflict with Israel.
Recent satellite imagery from February showed fresh concrete laid on one of the entrances. Analysts confirmed that a boom pump used to deliver concrete was visible at the site. Experts at ISIS suggest these modifications aim to enhance protection against potential air strikes.
Nearby, defensive measures have also appeared at other nuclear sites, including sealing off tunnel entrances at the Isfahan facility and repairing structural damage at Natanz, indicating heightened security awareness.
Analysts believe that while the ongoing construction reflects Iran's efforts to secure its nuclear capabilities, it also underscores the urgency for diplomatic engagement. Rafael Grossi, head of the International Atomic Energy Agency, expressed the need for renewed negotiations as time is running out for constructive dialogue.
