The name comes from the two well (pozzi) heads. Because of Venice’s difficult location, surrounded by salt water, and unable to meet its fresh-water needs without collecting rain water, the city required wells to meet a very basic necessity. The well heads became an art form. Wells had to be protected at all cost, to the point that, at one time, anyone attempting to poison the water would be quartered. Until a certain period, there was a tax on wells. The Republic then decided that no one should enrich themselves from this water, so it began charging certain water-dependent trades, including Barbers or Painters, Tanners, etc., for their use of the precious liquid.