via Khmer Times, 27 August 2021: Restorations to the Bayon done literally by hand.
The restoring and strengthening the southwest corner structure of the third terrace of the Bayon temple took six months to finish and architects described that the work was done by hand without the help of machinery.
Some of the blocks have been replaced by new ones cut from the mountains, which are the same type of sandstone. They are newer than the previous ones, but architects have replaced less than 20% of all the original stones.
Meng Sovanlylin, an architect at the Angkor Park and Archeological Prevention’s Department of Conservation of Monuments, said that during the restoration process, the team focused on strengthening the wall of the terrace and the soil quality of the foundation.
Source: Section of Bayon temple restoration complete – Khmer Times