I think it's a stone oven. Used mostly for making bread. My wife's Gradmother had one similar that her Grandfather built. Her Gradmother used to make the best bread even after they stopped using the stone oven.
BTW, these are unbelievable pictures! Thanks for posting them. I wish I lived so close to the Corleones.
Interesting. Thanks. What made me really wonder is that there are no visible openings from what I could see, and it just looks out of place in the middle of the yard.
