वज्रधातु vajradhātu, Traditional Chinese: 金剛界; Pinyin: Jīngāngjiè; Romaji: Kongōkai) is a metaphysical space inhabited by the Five Tathagatas.
Where the flower lands helps decide which Buddhist figure the student should devote themselves to.
[1] In traditional Tangmi and Shingon halls, the Diamond Realm Mandala is hung on the west wall symbolizing the final realization of Mahāvairocana Buddha.
[2] In this setting, the Womb Realm Mandala is hung on the east wall, symbolizing the young stage of Mahāvairocana Buddha.
In Chinese Buddhism, the Diamond Realm Mandala is also associated with the Yogacara Flaming Mouth Ritual (瑜伽焰口法會), which is often conducted during the Chinese Ghost Festival in order to feed pretas and reduce their suffering.