Iran’s Hardened ‘Mount Machoosh’ Nuclear Site Remains Untouched Amid Strategic Challenges

Israel and the United States are closely monitoring the Iranian underground facility known as "Mount Machoosh," a complex tunnel system carved over years near the Natanz nuclear site. Despite its strategic importance, the site has not been targeted in recent military operations due to operational difficulties, high costs, and uncertainty about its current use.

Located about 1.5 kilometers south of the Natanz enrichment complex, the tunnels are dug deep, between 100 and 135 meters, into hard granite rock, making them highly resistant to airstrikes. The site resembles the Fordow enrichment facility, which was only significantly damaged after the U.S. employed B-2 bombers and bunker-busting bombs.

Initially, Mount Machoosh was reportedly used mainly for storing centrifuges and equipment that were not installed or operational, casting doubt on whether striking it would meaningfully delay Iran’s nuclear program. This was likely why it was not attacked in June 2025 when it was reportedly empty or nearly so. Since then, Iran has moved centrifuges and equipment from other damaged nuclear sites into the tunnels, but there is no confirmed active uranium enrichment there.

An effective strike would require precise intelligence on the location of centrifuges and production halls inside the mountain. An inaccurate attack could cause only superficial damage without destroying the heavily fortified infrastructure. The U.S. is considered the only actor capable of such an operation, using B-2 bombers and GBU-57 bunker busters. However, the Fordow strike reportedly used 14 bombs from a stock of about 20, indicating that a similar operation would demand replenishing munitions and complex logistics.

Timing remains critical: an early strike before the facility becomes fully operational might not significantly delay Iran, while a late strike risks allowing Tehran to operate a heavily fortified enrichment site. Meanwhile, satellite images show ongoing reinforcement work around tunnel entrances to maintain access post-bombing and complicate any ground assault.