US and Israel Eye Deep Underground Nuclear Facility at Iran's Kuh-e-Mashak
Satellite imagery reveals extensive 2026 construction at Iran's underground Kuh-e-Mashak nuclear site. As President Donald Trump warns of potential strikes, the Pentagon accelerates development of advanced bunker-busting munitions.
Satellite Imagery Reveals Major Construction at Iran's Kuh-e-Mashak Nuclear Site
Satellite imagery analyzed by the Center for Strategic and International Studies (CSIS) reveals a significant surge in construction activity throughout 2026 at the Kuh-e-Mashak site in Iran, suspected of housing a secret nuclear facility. Located roughly 225 kilometers south of Tehran and buried deep beneath a mountain near the Natanz nuclear complex, the underground site has seen extensive road development, tunneling reinforcement, and earth-moving operations over the past year, according to a CNN report.
Intelligence officials evaluate that the underground facility may serve as a secure shelter or operational hub for reviving Iran's nuclear program. Analysts note that while construction has shifted from active excavation to internal building and exterior fortification, the site is not yet believed to be operational for uranium enrichment. Nevertheless, Israeli assessments suggest Tehran may seek to transfer centrifuges or portions of its enriched uranium stockpile into the underground complex.
US Military Develops Next-Generation Bunker Busters for Deep Underground Targets
Despite threats from President Donald Trump that the United States could strike Kuh-e-Mashak, the site's deep granite fortification presents a formidable challenge, potentially exceeding the current reach of conventional US ordnance. In response, the Pentagon has accelerated a planning marathon and technology development cycle to engineer specialized weaponry capable of penetrating heavily fortified underground installations.
According to internal documents, shortly after the outbreak of military escalations, a program manager at a Pentagon agency dedicated to countering weapons of mass destruction approved an emergency contract valued at $1.2 million. The funds were allocated to rapidly repair a unique underground test facility at the White Sands Missile Range in New Mexico to conduct live-fire testing for classified capabilities. The US Air Force also issued a solicitation in June for next-generation bunker-busting munitions designed to replace the existing Massive Ordnance Penetrator (MOP).
Operational Planning and Strategic Implications
Weighing military options, the US military maintains operational plans to strike Kuh-e-Mashak, integrating the site into broader target packages amid heightened tensions. A source familiar with the matter stated that any potential strike plan would require deploying some of the heaviest conventional bombs in the American arsenal, though questions remain regarding whether existing ordnance can reach deep enough to neutralize subterranean assets.
According to the CSIS analysis, the Kuh-e-Mashak facility is likely intended for one of three core nuclear purposes: a centrifuge assembly plant, an enrichment facility, or a secure repository for sensitive nuclear weapons-related activities, such as uranium metal conversion. Observers note this follows the destruction of the metal conversion plant at the Isfahan nuclear facility by the IDF over the past year.
