A swimming pool, swimming bath, wading pool, or simply a pool, is a container filled with water intended for swimming or water-based recreation. There are many standard sizes; the largest is the Olympic-size swimming pool
Chemical disinfectants such as chlorine, bromine or mineral sanitizers, and additional filters are often used in swimming pools to prevent growth and spread of bacteria, viruses, algae and insect larvae. Alternatively, pools can be made without chemical disinfectants by using a biofilter with additional carbon filters and UV disinfection. In both cases, pools need to be fitted with an adequate flow rate.
Ancient Greeks and Romans built artificial pools for athletic training in the palaestras, for nautical games and for military exercises. Roman emperors had private swimming pools in which fish were also kept, hence one of the Latin words for a pool, piscina.