Donald Trump said again on Friday that the United States may soon strike Pickaxe Mountain, the underground complex near Natanz that is the last significant site linked to Iran's nuclear program still untouched after two wars.
What is it?
A mountain in the Zagros range in Isfahan province, about 1.5 kilometers south of the Natanz enrichment complex, with a large facility dug into it. The name is a small accident of translation. The mountain is cal led Kuh-e Kolang Gaz La, and kolang means pickaxe, so foreign analysts began calling the site Pickaxe Mountain. It is not what Iranians call the facility, and Iran has never given it a public name at all.
Why was it built there?
Because of the rock. Most of the surrounding range is sedimentary, but this mountain is hard, dense granite, which gives anything tunneled beneath it substantial natural protection. Construction began in the autumn of 2020, months after an explosion destroyed an above-ground advanced centrifuge assembly plant at Natanz in an attack widely attributed to Israel. Iran said at the time that the underground halls would replace it. The destroyed plant had been built to assemble roughly 6,000 advanced centrifuges a year, a capacity sized for the tens of thousands Iran expected to need as restrictions under the 2015 nuclear deal expired between 2025 and 2030.
What is inside?
Nobody outside Iran knows, which is the heart of the problem. The International Atomic Energy Agency has never been given access. A double security perimeter, a fence and a wall with a patrol route, rings the entire mountain and joins Natanz's own perimeter. There are two pairs of tunnel entrances, one on the east side and one on the west. Analysts assume they lead to a single facility, but even that is not certain.
Iran has said the site is for producing and assembling advanced centrifuges. The Institute for Science and International Security, which has tracked the construction by satellite for years, judges the space beneath the mountain large enough to hold considerably more: not only an assembly plant but a working enrichment plant capable of producing weapons-grade uranium, and probably enough room for weaponization work such as casting uranium metal and shaping it into weapon components.
Two further claims circulate, neither verified. One is that part of Iran's stockpile of uranium enriched to 60 percent, estimated by the IAEA at around 440 kilograms, has been moved there. The other, from an Israeli intelligence assessment reported by the Wall Street Journal, is that thousands of centrifuges were moved into the mountain last autumn. Neither Israel nor the United States has published evidence. The institute's reading of the imagery is that the facility is not yet operational, and that construction continues.
How deep is it?
At least 100 meters beneath the mountain, which stands 1,608 meters above sea level. There is a detail in those measurements worth noticing. The eastern entrances sit about 145 meters below the ridge; the western entrances about 100 meters. That 50-metre difference between the two sets of doors suggests the facility may have more than one level. Either way it is deeper than Fordow or Natanz, both of which the United States has bombed. (Read More)
