The pit of the belly or the digestive tract region of the body. This area holds special significance in Eastern thought as it is said to be the ideal seat for the consciousness and the spiritual center of the body. During Zen meditation, practicers are instructed to focus their concentration on the tanden, an area located two finger lengths below the bellybutton. This practice helps to bring about emotional calm and stability.
The hara has special purpose in many martial arts, as both a physical center of balance for the body and a mental draw of spiritual energy.
It is also said that breathing from the hara or stomach is ideal as it tends to be more relaxing than normal breath.
To quote the well-respected Zen master, Harada-Roshi:
"You must realize that the center of the Universe is the pit of your belly!"