In my wife's town in France there is a cave under the castle that belongs to no one, not even the city. There are a couple dozen individual wine caves, about 100 sq ft, that people store wine in. If you find one that the door has rotted away, you can put up a new door and it's yours. A friend did that, and one wall had partially collapsed so he cleaned it out, put a new door and lock and it was his. Under the rock debris he found about 50 bottles of wine, the oldest was a local white wine from 1921. He opened one for us, it was still excellent. My father in law was mad about not being invited since that was his birth year.. He also opened bottles of local red wine from the late 30's, late 40's, and early 70's.