1) Water well 
A Puteal is a classical water well wellhead built around a well`s access opening. Latin: from puteus (well) — plural: putealia. The enclosure keeps people from falling down a well otherwise open at grade level. When fit with a cast iron lid, as traditionally in the public squares, or campos, of Venice, Italy, both the citizens and water supply ....
wall round the top of a well
• (n.) An inclosure surrounding a well to prevent persons from falling into it; a well curb.
The stone structure around a well, usually circular and often decorated with sculpture.
Pu'te·al noun [ Latin , from puteus well.] (Architecture) An inclosure surrounding a well to prevent persons from falling into it; a well curb. Weale. 
In architecture a puteal is an enclosure surrounding a well to prevent persons from falling into it.