The main document of the International Nath Order is three manuscripts under the title Twilight Yoga. Twilight Yoga is the name Shri Gurudev Mahendranath gave to his teaching expressed as a yoga: the path between the two lights, liberation and enjoyment together.
The three manuscripts on this site are:
He wrote in The Phantastikos that these three are the main document of the Order. They are not a retreat brand, not a fourth aim, and not a substitute for initiation. Read them. This page only names the set.

