This was an extremely rare visit to one of Iran’s nuclear reactors.
No Western television news team had been allowed near one, let alone be allowed to film one.
It is one of Iran’s main research reactors and as such it is exactly the kind of facility that not only comes under the terms of Iran’s nuclear deal with six world powers, but it’s also the kind of facility that international inspectors will be monitoring very closely with the co-operation with the Iranian government.
I was also given an exclusive interview with Behrouz Kamalvandi, the spokesman for the Atomic Energy Organisation of Iran and deputy director of the organisation’s international department.
Talking to me in headquarters of Iran’s primary nuclear organisation, he was comfortable, relaxed and engaging.
We spoke on a wide range of topics from the debate within Iran about whether the deal was good for the country, and the importance of managing expectations inside Iran and internationally at the pace at which the highly technical and complex primary provisions of the accord would now be put into place.
Mr Kamalvandi told me the deal was the best that both sides could get, re-iterating that it was the product of an intense negotiation process involving seven nations and the International Atomic Energy Agency over many years, starting as far back as 2003-5.
The lifting of sanctions is the key wish and hope for most ordinary Iranians but that will not happen immediately, as Iran had argued for.
Instead, the sanctions will be lifted once international inspectors verify that Iran has started implementing key conditions such as the dismantling of thousands of centrifuges, the large scale modifications of the Arak heavy water plant and the export to a third country of tens of thousands of kilos of Iran’s enriched Uranium.
Mr Kamalvandi said this would now start but that Iran would do this “cautiously” rather than precipitously.
On the sensitive subject of the interviewing of Iran’s nuclear scientists and technicians, Mr Kamalvandi said that this would happen but under specific and carefully agreed conditions.
He said that it would not be done under the “fabricated” pretext of searching for earlier programmes which had “possible military dimensions” - in the world would accept its scientists being interviewed as though they were the accused in a court of law.
However, Mr Kamalvandi was in no doubt about the wider and profound importance of the agreement reached in July.
He agreed it was a truly historic achievement for all sides, showing that enemies even with the deepest divisions and mistrust can overcome their differences if they talk to each other rather than trying to use force.