the ‘elixir’ is cultivated in the area of the lower tanden, the ‘elixir field’ or ‘cinnabar field,’ also called the kikai tanden, ‘the ocean of ki-energy,’ the center of breathing or center of strength, located slightly below the navel.
Hakuin’s commentator identifies the cinnabar field as the lower tanden, the somatic center where vital energy accumulates, and situates it within both Taoist internal alchemy and Zen meditative practice.
, Wild Ivy: The Spiritual Autobiography of Zen Master Hakuin, 1999thesis