Ancient Greeks and Romans built artificial pools for athletic training in palaestras, for nautical games and military exercises. Roman emperors had private swimming pools where the fish were also observed, and therefore one of the Latin word for pool, piscina.The first heated swimming pool was built by Gaius Maecenas of Rome in the first century BC. Gaius Maecenas was a rich Roman lord and considered one of the first patrons of artsAbove ground pools consisting of a side wall, a waterproof lining, and a frame or superstructure to support and reinforce the sidewall. The frame unit typically includes a lower rail and a top rail of the pool side wall is attached. The mesh is attached to an inner side of the pool side wall along the upper edge.