Imagery Update: Iran Continues to Harden its New Natanz Tunnel Complex [1] – Institute for Science and International Security
by David Albright and Sarah Burkhard
May 5, 2022
This report is an imagery update of earlier reports on the construction progress at the new Natanz tunnel complex, located under a mountain south of the main uranium enrichment site. Commercial satellite imagery from March and May 2022 show new, long extensions at two tunnel entrances, likely to be covered by earth to further protect and secure the entrances. In parallel, construction inside the tunnel appears to be progressing steadily. Major excavation efforts appear completed, while tunnel lining work appears to be ongoing, as well as clearance activities for a possible fourth tunnel portal. It now appears possible that the site could be ready for initial operation in 2022. Based on official Iranian accounts, the new tunnel complex will house a new centrifuge assembly facility to replace the Iranian Centrifuge Assembly Center (ICAC) destroyed in an attack in July 2020. However, a recent Institute analysis found that the new tunnel complex will likely be more deeply buried than Fordow and have significantly more floor space, raising questions about other sensitive nuclear activities at the site, most worrisome, enrichment activities.
Construction Progress
Figure 1 provides an overview of the Natanz tunnel complex as of March 8, 2022, with three visible tunnel portals (two eastern portals and one western portal) and a possible fourth one being constructed. Newly visible since the Institutes January 2022 update are new extensions at two tunnel entrances, one at the western tunnel portal and one at the eastern auxiliary entrance.
Figures 2 and 3 show the tunnel entrances and their extensions in March, situated in a channel of excavated rock, allowing future coverage with earth and providing significant additional protection to the tunnel portals. By May 2022, the eastern tunnel entrance extension is covered, while the extension at the western main portal appears to be in progress (see Figures 4 and 5).
Water appearing to flow from the eastern main portal, previously visible in November 2021, is visible again in May 2022. It is unknown if the water is uncontrolled outflow from the eastern main portal, representing an unexpected construction challenge.
Surrounding spoil piles remained largely unchanged since November 2021, indicating that boring and excavation of the underground complex are largely complete. The addition of a probable concrete batch plant, continued presence of heavy construction equipment and usage of dirt roads, as well as previously visible probable shotcrete equipment indicate that the concrete lining of the complex walls is well underway and that final lining and reinforcement operations of the tunnel complex are ongoing. The possible fourth tunnel portal would likely be constructed relatively quickly and segue into the existing tunnel. A spoil pile associated with road grading and clearance of the area appears to grow quickly.
There has been no visible evidence of centrifuge manufacturing or centrifuge-related equipment being moved into the tunnel complex. It may be possible that such transfers could occur later this year or early next year.
Figure 1. A March 2022 overview image of the tunnel complex under construction south of the main Natanz enrichment plant.
Figure 2. One of the two eastern tunnel portals shows a likely permanent tunnel entrance extension, adding further protection to the entrance.
Figure 3. The western tunnel entrance also features a new entrance extension, likely to be covered by earth in the future, as of March 2022.
Figure 4. The eastern tunnel entrance extension is covered in May 2022.
Figure 5. The western tunnel entrance extension appears to have progressed slightly.
1. David Albright, Sarah Burkhard, and John Hannah, Irans Natanz Tunnel Complex: Deeper, Larger than Expected, Institute for Science and International Security, January 13, 2022, https://isis-online.org/isis-reports/detail/irans-natanz-tunnel-complex-deeper-larger-than-expected/8
- Graham called yearslong push for war with Iran the best thing Ive ever done in new footage - CNN - July 26th, 2026 [July 26th, 2026]
- Unreleased Documentary Footage Captures Grahams Obsessive Push for Iran War - WSJ - July 26th, 2026 [July 26th, 2026]
- Netanyahu: Iran conflict ends when regime falls or gives up its nuclear program - The Times of Israel - July 26th, 2026 [July 26th, 2026]
- Netanyahu reined in Lindsey Grahams obsessive push to widen Iran war, footage shows - Ynetnews - July 26th, 2026 [July 26th, 2026]
- US strikes 'on a hold,' as talks, battle for Strait of Hormuz control loom with Iran - Fox News - July 26th, 2026 [July 26th, 2026]
- Live updates: Iran operations on a hold after almost two weeks of consecutive US strikes, source says - CNN - July 26th, 2026 [July 26th, 2026]
- Will America launch another massive attack on Iran? - The Economist - July 26th, 2026 [July 26th, 2026]
- US pauses attacks on Iran for a second day as peace talks continue - The Guardian - July 26th, 2026 [July 26th, 2026]
- Trump's Aides Reveal New Levels of Erratic Behavior Over Iran War - The Daily Beast - July 26th, 2026 [July 26th, 2026]
- US, Iran Extend Pause in Strikes as Oman Holds New Hormuz Talks - Bloomberg.com - July 26th, 2026 [July 26th, 2026]
- Iran war latest: 'They would use it if they had it' - Trump insists Iran cannot have a nuclear weapon - Sky News - July 26th, 2026 [July 26th, 2026]
- Iran threatens to expand war if US resumes strikes, which it says Israel is pushing for - The Times of Israel - July 26th, 2026 [July 26th, 2026]
- What to know about Iran's Pickaxe Mountain, home to an underground nuclear site threatened by Trump - AP News - July 26th, 2026 [July 26th, 2026]
- Vance, Caine raised concerns about escalating war in Iran, sources say as US pauses consecutive nights of strikes - CNN - July 26th, 2026 [July 26th, 2026]
- US pauses attacks on Iran for a second straight day and Tehran does too - Orange County Register - July 26th, 2026 [July 26th, 2026]
- Katy Perry deeply appalled over White House using her song in Iran war video - The Guardian - July 26th, 2026 [July 26th, 2026]
- It Isnt Just Pickaxe: Trumps Other Potential Nuclear Targets in Iran - WSJ - July 26th, 2026 [July 26th, 2026]
- Iran Journey Reveals Societys Wartime Defiance and Hope - The New York Times - July 26th, 2026 [July 26th, 2026]
- CBS News poll finds Iran conflict marked by feelings of uncertainty; most say it's more difficult than Trump had expected - CBS News - July 26th, 2026 [July 26th, 2026]
- Military Families Express Outrage After Pentagon Lowers Number of U.S. Troop Deaths in Iran War - The New York Times - July 26th, 2026 [July 26th, 2026]
- Ukraine war briefing: Iran accuses Kyiv of deadly attack on Iranian vessel in Caspian Sea - The Guardian - July 26th, 2026 [July 26th, 2026]
- Iran war spreads to Red Sea and Caspian, Gulf quiet as US forgoes strikes - Reuters - July 26th, 2026 [July 26th, 2026]
- Airstrikes have paused and talks are pressing forward. But can the US and Iran take the off-ramp? - AP News - July 26th, 2026 [July 26th, 2026]
- The U.S. and Iran pause attacks on each other for a 2nd day as Tehran talks with Oman over Hormuz - Fortune - July 26th, 2026 [July 26th, 2026]
- Iran reports first night without new US strikes as Houthis attack Saudi Arabian city - Fox News - July 26th, 2026 [July 26th, 2026]
- U.S. and Iran pause air strikes as talks show signs of progress - The Globe and Mail - July 26th, 2026 [July 26th, 2026]
- Opinion | I was a diplomat in Iran. Two rules explain its actions. - The Washington Post - July 26th, 2026 [July 26th, 2026]
- Trump is giving Iran talks 'a little bit of room,' US ambassador to UN says - Reuters - July 26th, 2026 [July 26th, 2026]
- How Russia helped build Iran into a strategic partner against the West - analysis - The Jerusalem Post - July 26th, 2026 [July 26th, 2026]
- U.S. forgoes strikes on Iran, but conflict escalates in the Red Sea - NBC News - July 26th, 2026 [July 26th, 2026]
- US has spent $37.5B on Iran war, Hegseth says at heated Senate hearing - USA Today - July 21st, 2026 [July 21st, 2026]
- Israel remains on sidelines of US-Iran fight, which for Jerusalem is just fine for now - The Times of Israel - July 21st, 2026 [July 21st, 2026]
- Secretary Hegseth grilled over growing cost of war with Iran - NBC News - July 21st, 2026 [July 21st, 2026]
- Trump Has Only Terrible Choices With Iran - The Atlantic - July 21st, 2026 [July 21st, 2026]
- Hegseth asks for billions for the Iran war, is there an end game? - NPR - July 21st, 2026 [July 21st, 2026]
- Secretary Hegseth testifies on Capitol Hill as Iran conflict costs rise to $37.5 billion - KCRA - July 21st, 2026 [July 21st, 2026]
- Opinion | The U.S. military's escalating strikes in Iran may be legal. That doesnt make them justified. - MS NOW - July 21st, 2026 [July 21st, 2026]
- Secretary Hegseth testifies on Capitol Hill as Iran conflict costs rise to $37.5 billion - WBAL-TV - July 21st, 2026 [July 21st, 2026]
- Secretary Hegseth testifies on Capitol Hill as Iran conflict costs rise to $37.5 billion - WYFF - July 21st, 2026 [July 21st, 2026]
- Trump says will be hitting Iran's Pickaxe Mountain nuclear complex 'pretty soon' - France 24 - July 21st, 2026 [July 21st, 2026]
- Secretary Hegseth testifies on Capitol Hill as Iran conflict costs rise to $37.5 billion - WESH - July 21st, 2026 [July 21st, 2026]
- Secretary Hegseth testifies on Capitol Hill as Iran conflict costs rise to $37.5 billion - WDSU - July 21st, 2026 [July 21st, 2026]
- Secretary Hegseth testifies on Capitol Hill as Iran conflict costs rise to $37.5 billion - KETV - July 21st, 2026 [July 21st, 2026]
- Pentagon Identifies Another Soldier Killed in Iran War - The New York Times - July 21st, 2026 [July 21st, 2026]
- Secretary Hegseth testifies on Capitol Hill as Iran conflict costs rise to $37.5 billion - KSBW - July 21st, 2026 [July 21st, 2026]
- The Iran wars big oil mystery: No one seems to want it - CNN - July 21st, 2026 [July 21st, 2026]
- Second critical waterway threatened by Iran war - CNN - July 21st, 2026 [July 21st, 2026]
- Iran is evading U.S. defenses to kill and wound American soldiers it's not just that "one leaked through" - CBS News - July 21st, 2026 [July 21st, 2026]
- July 20, 2026 US completes more strikes against Iran after Trump warning to Tehran - CNN - July 21st, 2026 [July 21st, 2026]
- Pentagon Withheld Dozens of U.S. Military Injuries in Iran War - The New York Times - July 21st, 2026 [July 21st, 2026]
- Hegseth is facing questions from senators over funding for the Iran war - Yahoo - July 21st, 2026 [July 21st, 2026]
- US launches fresh strikes on Iran, as Trump warns of retaliation for deaths of soldiers - BBC - July 21st, 2026 [July 21st, 2026]
- U.S. strikes unlikely to move Iran, intelligence reports say - The Washington Post - July 21st, 2026 [July 21st, 2026]
- US military slow to disclose Iran war injuries with officials citing security needs - CNN - July 21st, 2026 [July 21st, 2026]
- On sidelines of Iran war, Israel is readying plans in case of escalation - CNN - July 21st, 2026 [July 21st, 2026]
- Oil Buyers Battered by the Iran War Energy Crisis Race to Build Buffers - The New York Times - July 21st, 2026 [July 21st, 2026]
- Attacks between US and Iran across Mideast overshadow efforts to keep diplomacy alive - AP News - July 21st, 2026 [July 21st, 2026]
- The Pentagon, sinking billions into Iran war, is quickly running short on cash - Yahoo - July 21st, 2026 [July 21st, 2026]
- WATCH: Hegseth, Caine defend Trump's funding request to Congress as Iran war reignites - PBS - July 21st, 2026 [July 21st, 2026]
- To Base or Not to Base: The Iran War Exposes Flaws of U.S. Bases in the Middle East - Council on Foreign Relations - July 21st, 2026 [July 21st, 2026]
- Mission in Iran war has pivoted toward ensuring oil flow, Trump official says - The Guardian - July 20th, 2026 [July 20th, 2026]
- US bombing of Iran expands as American troops killed and Tehran retaliates against the Gulf states - AP News - July 20th, 2026 [July 20th, 2026]
- US strikes Iran for ninth day; Iran says two oil tankers in Strait of Hormuz exploded and immobilised - Reuters - July 20th, 2026 [July 20th, 2026]
- Iran Update Special Report, July 19, 2026 - Institute for the Study of War - July 20th, 2026 [July 20th, 2026]
- U.S. teeters on return to all-out war with Iran after more troops killed - The Washington Post - July 20th, 2026 [July 20th, 2026]
- Nigerian children pay the price for the Iran war as malnutrition and poverty surge - PBS - July 20th, 2026 [July 20th, 2026]
- US strikes Iran for 9th straight night; IRGC launches retaliatory attacks on several Arab countries - The Times of Israel - July 20th, 2026 [July 20th, 2026]
- CENTCOM Ends Weekend Wave of Strikes Against Iran - centcom.mil - July 20th, 2026 [July 20th, 2026]
- The U.S. strikes Iran after Trump announces a renewed blockade and tolls in Hormuz - NPR - July 20th, 2026 [July 20th, 2026]
- Trump asks Congress to add Iran to Russia sanctions bill - MS NOW - July 20th, 2026 [July 20th, 2026]
- What remains of the Iran deal as fighting rages - AP News - July 20th, 2026 [July 20th, 2026]
- US launches more airstrikes against Iran after announcing another death of a service member - AP News - July 20th, 2026 [July 20th, 2026]
- US releases footage of ninth consecutive night of strikes on Iran - Al Jazeera - July 20th, 2026 [July 20th, 2026]
- The renewed US-Iran conflict is escalating and threatening to spin out of control - CNN - July 20th, 2026 [July 20th, 2026]
- US bombing of Iran expands as American troops killed and Tehran retaliates against the Gulf states - The Boston Globe - July 20th, 2026 [July 20th, 2026]
- US bombing of Iran expands as American troops killed and Tehran retaliates against the Gulf states - ClickOnDetroit | WDIV Local 4 - July 20th, 2026 [July 20th, 2026]
- US bombing of Iran expands as American troops killed and Tehran retaliates against the Gulf states - Click2Houston - July 20th, 2026 [July 20th, 2026]
- US bombing of Iran expands as American troops killed and Tehran retaliates against the Gulf states - WAVY.com - July 20th, 2026 [July 20th, 2026]
- US bombing of Iran expands as American troops killed and Tehran retaliates against the Gulf states - KSAT - July 20th, 2026 [July 20th, 2026]
- U.S. death toll rises again as Iran war escalates over the weekend - CNBC - July 20th, 2026 [July 20th, 2026]