Dounreay radioactive waste storage vaults constructed
20 August 2012 Last updated at 10:24 BST
Construction workers have just finished digging and blasting out two of the biggest holes in the ground in Scotland.
The work is part of the first phase of a project to build a series of huge vaults which will contain all the low-level radioactive waste from the demolition of the Dounreay nuclear plant.
BBC Scotland's Craig Anderson has been to the site on the Caithness coast.