Deep in the rocky mountains of Iran's Isfahan Province, a mysterious underground installation stands, sparking global concern. Known as Mount Kapak (Kuh-e Kolang Gaz La), this defense site is claimed to possess extraordinary protection, making it nearly impossible to penetrate, even by the US military's most advanced bunker-buster bombs.
Located about two kilometers from the Natanz uranium enrichment complex and 220 kilometers south of Tehran, the facility is reportedly situated at a depth of at least 100 meters under a very thick layer of granite rock. Satellite imagery analysis shows that construction of this one-square-kilometer area began in late 2020, following an incident of alleged cyber sabotage that previously damaged the Natanz facility.
Tehran insists that the complex is specifically designed as an assembly center for the latest generation of centrifuges for their energy program. However, US and Israeli intelligence services suspect the existence of these giant tunnels as an alternative location to secretly relocate high-level uranium enrichment activities to evade international surveillance.
Tensions rose further following the outbreak of geopolitical conflict involving the US, Israel, and Iran in early 2026. President US Donald Trump openly issued military threats targeting the area, asserting that Washington continues to monitor every movement and potential transfer of nuclear material into the depths of Mount Kapak.
Responding to the bluster, the Iranian Foreign Ministry strongly denied any illegal nuclear activity at the site. The Iranian side asserted that all of their nuclear programs run transparently under the supervision of the International Atomic Energy Agency (IAEA), while accusing the US of using the Mount Kapak issue merely as a pretext to justify acts of aggression and sabotage.
A number of strategic research institutions, including the Institute for Science and International Security (ISIS), assess that destroying this bunker through airstrikes would be extremely difficult due to its sturdy natural defense structure. Analysts estimate that disabling the installation would likely require a direct ground operation, given that Mount Kapak's physical protection exceeds the penetration capabilities of current conventional bunker-buster warheads.
