If one sold a house to his fellow, neither the house's pit nor its cistern (dug into the ground and used as water reservoirs) are included in the sale, even if the seller wrote in the deed, “I am selling the depth and height of the house.”
However, to get to the cistern, the seller has to purchase the right-of-way from the buyer, in the opinion of Rabbi Akiva. According to him, the typical inclination of one who sells something is to transfer it in full and generous fashion, without reserving anything for himself. In this case, by not saying anything, he transferred the right-of-way also. The Sages disagree and say that typically the seller wants to sell no more than he has to, retaining the right to pass through the house to reach the cistern.