Update(1605ET): Where is Iran's Uranium? Truce Highlights Mystery Over Stockpile... that's Bloomberg's latest headline over the 'biggest mystery' that remains in the war. There's also the pressing question of whether Trump's massive airstrikes from B-2 bombers actually truly destroyed the facilities and these stockpiles. 

The Iranians aren't dumb, and likely took drastic steps to further protect, conceal, or likely move these enriched stockpiles - some 400kg according to most reports - as wave after wave of Israeli warplanes hit Iran, significantly before the US sent its bombers this past weekend. It appears core components are still intact - though Iran has long maintained it is merely for peaceful nuclear energy development. 

The NY Times is currently reporting that the US operation merely set Iran's nuclear program back by a few months. And further:

US BOMBS DIDN'T COLLAPSE UNDERGROUND IRANIAN NUKE BUILDINGS: NYT

Big media allegations, based on US officials and an intel assessment, that the Iranians moved their enriched uranium: