Sphaeristerium
Sphaeristerium (Latin; from the Greek σφαιριστήριον; from σφαῖρα, ball) is a term in Classical architecture given to a large open space connected with the Roman thermae for exercise with balls after the bather had been anointed. They were also provided in Roman villas. Sports. In Italian "sferisterio" is nowadays the courtfield for tamburello and two different pallone varieties: "pallone col bracciale" and "pallone elastico". These are rectangular smooth grounds with a high wall on one of the long sides. Sizes change depending on the variety: wide and long for the "pallone col bracciale", and and for the "pallone elastico