The fourth Chakra is located behind the heart, toward the back and middle of the chest. When you concentrate, concentrate on your Dahn-joong marked by the slight indentation on your chest, or sternum…

Using your fingers, press on your Dahn-joong. Now release the pressure of your fingers. Concentrate on the point just behind the pressure. Breathe in slowly and let your chest expand. Breathe out and let your chest contract. Breathe in… and breathe out… Imagine the breath streaming in and out of your Dahn-joong. Concentrate on the fourth Chakra, and expand the sensation. You are feeling the source of energy for love and devotion. Gently probe the state of your heart. Do you feel blocked or open, comfortable or stuffy? When the fourth Chakra is weak, The ‘Im Maek‘ , a major meridian running through the chest, becomes blocked

From Healing Chakra by Ilchi Lee