Fordo is ground zero for Iranian nuclear weapons research and development. Unless ALL of Iran is open to inspections there can be no verifiable agreement.
This is incorrect information circulated by Iran hawks prior to the Framework Agreement. Fordow is to be made into an international research center, and they won't be enriching uranium there for 15 years. Further: "Almost two-thirds of Fordow’s centrifuges and infrastructure will be removed. The remaining centrifuges will not enrich uranium. All centrifuges and related infrastructure will be placed under IAEA monitoring."