On Friday three strong young me,(not including me) smashed the hell out of the stone with a sledge hammer and a sort of manual jackhammer ("The perfect thing for a hangover," said one of the students. There had been free beer at the end-of-week party the night before.)
That reduced the rock to about the size of a microwave oven and four strong men, (again not including me) tied ropes to it and pulled it out.
Then I got to spend a happy two hours digging down in the pit. See the photo by John Vanee. Found my first pottery handle. Bosses occasionally came by and said, in amazement "Are you still finding pottery down there?" I would toss up my latest find and keep going.
Ephrat pointed out a weird arch on one side that appeared to be different from the rest of the put. And on the next workday Felix and Tibor broke through it and found a smaller hole (room?) made of softer earth. Perhaps more will be revealed.