What is Pickaxe Mountain, the Iranian nuclear facility Trump is threatening to strike?

President Donald Trump has threatened to bomb the Iranian underground nuclear facility Pickaxe Mountain, ratcheting up tensions between the U.S. and Iran.

The president’s comments have put renewed focus on one of Iran’s most secure and protected facilities.

It comes as U.S. Central Command has bombed Iranian targets for 11 straight nights, including military operations centers, drone storage facilities, and military logistics infrastructure as it seeks to weaken the country’s ability to control commercial shipping in the Strait of Hormuz.

U.S. and Iran had signed an interim memorandum of understanding on June 17 that halted military operations, called for the reopening of Hormuz and established a 60-day window for negotiating a permanent agreement, including terms covering Iran’s nuclear program. But the document left the future management of the Strait of Hormuz unresolved.

Here’s what we know about the latest point of tension between the U.S. and Iran.

Speaking from Washington on Tuesday, the president said that the U.S. military will soon be targeting Pickaxe Mountain — a key underground site next to an Iranian nuclear facility.

“We’ll be hitting that area very probably pretty soon, and there’s not a thing they can do about it. Normally I wouldn’t say that; if I thought they could do something about it I would never say that, but we’ll be hitting that area pretty soon, and very heavily,” Trump told reporters in the White House.

Trump issued similar threats earlier in the month on the Hugh Hewitt Show: “We’re watching [Pickaxe Mountain] closely. We see no ⁠activity there. They’re not doing well with their nuclear ​situation. Every time we hear about it, we blow ​it up. So they don’t like talking about it. But we’ll probably give Pickaxe a shot relatively soon.”

If the U.S. were to proceed with such an attack, it will be considered as “an explosion of war in the region,” Iran’s Khatam Al-Anbiya military command said in translated comments reported by state-run broadcaster IRIB. They added that “all the interests of America, the allies and supporters” would then be the target of a “powerful attack by the armed forces of the Islamic Republic of Iran.”

Located south of Iran’s Natanz enrichment plant, Pickaxe Mountain, or Kuh-e Kolang Gaz La as it is known in Iran, began construction in 2020. At the time, Iran said the underground facility would replace a destroyed centrifuge plant at Natanz, which would have seen 6,000 nuclear centrifuges assembled per year, according to the Institute for Science and International Security (ISIS).

The mountain has a height of 1,608 meters above sea level, while the facility is estimated to be 100 meters deep under the mountain, per ISIS.

Since the U.S. struck three Iranian nuclear sites in June 2025, including Natanz, Fordow and Isfahan, construction at Pickaxe Mountain has accelerated, according to satellite image analysis by the Center for Strategic and International Studies.

CSIS determined that Iran has constructed security walls around the whole site, with tunnels to the west, east, and south.

“It remains unclear when Pickaxe Mountain could be operational, based only on assessments of satellite imagery,” researchers at ISIS said in a July 14 note. “It is also unclear if Iran still plans on installing a large-scale assembly facility, given the destruction of Iran’s centrifuge program, including Iran’s ability to make centrifuge components needed for an assembly plant.”

— CNBC’s Lim Hui Jie and Emma Graham helped contribute to this report.