The international atomic watchdog has been to some of the world's toughest locations, but nothing quite like Europe's largest nuclear power plant in an active war zone.
International Atomic Energy Agency
Amano, who was director general of the International Atomic Energy Agency, was instrumental in negotiations leading to the 2015 deal with Iran to limit its nuclear program.
Secretary of State John Kerry said the move was "one of the most significant steps" in fulfilling the July nuclear agreement between Iran and six world powers.
A nuclear agreement with Iran hinges on the work of nuclear inspectors. Here's a close-up look at how they train to do their job.