Pl.: tholoi)
Gk: θόλος

A round room covered by a dome. This dome could have a circular opening in its centre to permit air and light to enter. In Greek-style baths, such rooms were often equipped with single-person hip-baths. In Roman-style baths, especially in early examples, round rooms were first used as sweat rooms, heated by a brazier. In several Pompeian and Herculanean baths, this sweat room was later transformed into a cold pool.