Daoist neidan, internal alchemy, names the lower dantian, xia dantian, located roughly three finger-widths below the navel and inward toward the spine, as the body's principal furnace for refining qi, the site where jing is first transformed into qi before the ascent to shen described in the tradition's three-stage sequence. Qigong and taijiquan practice both center on this point, directing breath and attention there, yi shou dantian, "the mind guards the dantian," a basic instruction repeated across schools, on the understanding that qi gathered and stored there becomes available to circulate through the meridians and to be refined further.
Daoist texts also describe a middle dantian at the center of the chest, linked to qi and to emotional balance, and an upper dantian between the eyebrows, linked to shen and to spiritual perception, but the lower dantian receives the overwhelming majority of practical instruction, since Daoist alchemy treats it as the necessary foundation the other two depend on. The lower dantian sits on the body's midline along the Conception Vessel, the meridian Chinese medicine treats as the sea of yin qi, giving the alchemical center a specific anatomical channel through which its stored qi is understood to connect to the rest of the body.