A secret training grounds is a place where a person can go to train and become stronger without having to do so publicly, allowing them to 1. focus more on training, or 2. hide from others while training.
Urahara Shop training ground
Before beginning his mission into Soul Society to rescue Rukia Kuchiki, Kisuke Urahara takes Ichigo Kurosaki to a huge secret training ground beneath the Urahara Shop, intended to resemble the Sōkyoku Hill training ground. Here, over a period of several days, Urahara helps Ichigo regain his lost Shinigami powers and teaches him the basic techniques of Shinigami combat. Ichigo's partial transformation into a Hollow also takes place here, and Urahara opens the Senkaimon into Soul Society from this room.
The Urahara Shop training ground is a large room with a ceiling and walls painted to resemble a cloudy sky over a floor of desolate, brown, craggy land dotted with dead trees. Urahara claims to have built the room, using Soul Society's technology, in a single day and night.
The training ground is used again by Yasutora Sado as he spars with Renji Abarai to master higher levels of his power; from there, Ichigo, Chad, and Uryū Ishida make their way through the Garganta into Hueco Mundo.
Sōkyoku Hill training ground
Urahara styled his shop's secret training ground on one he built beneath Sōkyoku Hill while young. In this training ground, he and Yoruichi Shihōin would play and train. When Ichigo Kurosaki narrowly escapes defeat by Byakuya Kuchiki, Yoruichi takes him to this training ground in order that he might rapidly attain Bankai through use of the Tenshintai. Renji also attains Bankai in this space.
While very similar in appearance to the Urahara Shop's training ground, the Sōkyoku Hill training ground also sports a hot springs whose waters have the power of healing injuries.
Visored warehouse training ground
Beneath the Visored's warehouse hideout is another secret training ground, bearing a strong resemblance to those beneath the Urahara Shop and the Sōkyoku Hill. Ichigo's mastery of his inner Hollow and his training with the Visored takes place here; Orihime Inoue also meets and befriends Hachigen Ushōda here as he heals Tsubaki.
Karakura Hospital training ground
Ryūken Ishida has constructed a training area inside Karakura Hospital. In this stark, metallic chamber, Ryūken fights Uryū to exhaustion, finally shooting him with a Quincy Spirit Arrow to restore his lost abilities.
- ↑ Bleach manga, chapter 130 page 9
- ↑ Bleach manga; Chapter 59, page 12
- ↑ Bleach manga; Chapter 130, page 7