Situated roughly ninety to one hundred kilometres southwest of Tehran, the Fordow Fuel Enrichment Plant operates beneath Mount Oroum in a mountainous region near the city of Qom.

Its underground halls, believed to extend between eighty to three hundred feet below the surface, house two main centrifuge tunnels, supplemented by multiple smaller access passages .

The facility emerged publicly in two thousand nine after covert construction began around two thousand six.

Iran informed international inspectors later that year, citing anticipated military threats and presenting Fordow as a contingency backup for its Natanz plant .

Under the two thousand fifteen nuclear accord, Fordow was to convert into a research site, limitations were imposed on enrichment and centrifuge use, and it was placed under enhanced international surveillance.

Iran gradually reversed these constraints after two thousand eighteen, resuming uranium enrichment activities, reportedly operating advanced IR‑6 centrifuges with enrichment levels reaching approximately sixty per cent .

Iran has intensified fortifications at its nuclear complexes, including new tunnel networks near Natanz, amid ongoing diplomatic discussions aimed at restoring constraints under the two thousand fifteen agreement .