On the tip of your nose...

Focusing on the tip of the nose is the highest lock. It is referred to as Lotus Point Meditation. This controls the mind, which is locked in a triangle. When the optic nerve concentrates at the tip of your nose, the ida and pingala, then the sushmuna get to a center of balance. This stimulates the pineal glad and the frontal lobe of the brain. New energy pathways are created in the brain.

Whenever you meditate on the tip of your nose, the frontal lobe will become hard. As you meditate more, it will become like lead. And the funny thing is the, one day automatically it will not be lead. It "breaks." You will have intuition to see the unseen, know the unknown, and hear the unheard, and your life will not be the same as it is now.

-Yogi Bhajan