Although Tantra is very popular, not many people understand its real meaning. Some people deny Buddha's Tantric teachings while others misuse them for worldly attainments. Actual Tantra, also known as 'Secret Mantra' or 'Vajrayana', is a special method taught by Buddha to purify our world, our self, our enjoyments and our activities. If we put this method into practice following the instructions of a qualified Tantric Spiritual Guide we will very quickly attain enlightenment. In this authoritative book Venerable Geshe Kelsang Gyatso Rinpoche provides a detailed and comprehensive explanation of the essential practices of the four classes of Tantra as taught by Buddha. Drawing on his own experience from many years in Tantric retreat he shows how people in the modern world can enter, make progress on, and finally complete the Vajrayana path to enlightenment.