The Seishin to Toki no Heya (精神と時の部屋 Seishin to Toki no Heya?, literal meaning "Spirit and Time Chamber"; Funimation: "Hyperbolic Time Chamber", Viz: "Chamber of Spirit and Time") is a dimension is a room inside the Castle of God.
Son Gokou entered the Seishin to Toki no Heya during his training with Kami-sama for his match against Piccolo in the 23rd Tenkaichi Budoukai. While in the room, Gokou shot up in height but only spent one month in there because he could not handle the atmosphere.
Androids and Cell ArcEdit
Sixth Universe ArcEdit
Dende later fixed the Seishin to Toki no Heya, and Gokou and Vegeta trained in the room during the five days before the Sixth Universe and Seventh Universe Gods of Destruction Selection Martial Arts Competition for three days.
"Future" Trunks ArcEdit
After his defeat against Gokou-Black and Zamasu, Vegeta trained in the Seishin to Toki no Heya while Gokou learned the Mafuuba to seal away the immortal Zamasu. After half a day, Vegeta exited the room while destroying it.
Universe Survival ArcEdit
Hours before the Tournament of Power, Vegeta entered the recently fixed room to train.