I recently got a copy of an old article written by B.P. Groslier detailing some of the archaeological discoveries in Cambodia during the 1960s. They include a photo of some of his famous work at the Memot (also spelled Mimot) circular earthworks (see here and here for more info).
There is also a great photo (below) of an excavation, although I can’t seem to find the caption about where it is. I suspect it might be Sambor Prei Kuk. I just love the little railroad tracks they’re using to car off excess dirt, it’s very Indiana Jones.
Groslier, Bernard Phillippe
1966 Découvertes archéologiques récentes au Cambodge. Kambuja 16 :76-81.