Sent in by a roving correspondent:
I'll attempt to answer my own question. These were found at the beach and, according to the person who took them, have been there for about a month. They appear to be the domes for the various towers that will grace the NEW Casino building. You are free to speculate what they might also be under comments below. Our intrepid reporter also observed that there were lights on in "Building A" - which means that some sort of temporary power has been extended to the building.