Sucrerie Diamant?
While I was in Concordia, I ran into these ruins near a rental car lot all the way down the road from the EDF building. According to an archaeological map I found, it seems this might be Sucrerie Diamant, but other than that I have no info on it. The map I found does show the location of the Sucrerie Friars’ Bay, which may be helpful since I wasn’t able to find that before.