(Sanskrit निर्वाण, "extinction" or "cessation"; Tibetan: nyangde, literally "the state beyond sorrow") In general use, the word nirvana refers to the permanent cessation of suffering and its causes, and therefore refers to a state of consciousness rather than a place. Yet, the term can also apply to heavenly realms, whose vibration is related to the cessation of suffering. In other words, if your mind-stream has liberated itself from the causes of suffering, it will naturally vibrate at the level of Nirvana (heaven).
￼"Samsara, ‘circling,’ is to spin from one place to another. Nirvana is to have cut through this circling." - Padmasambhava, The Cycle of Vital Points
“Samsara and Nirvana have no difference than that between the moment of being unaware and aware, since we are not deluded by perception but by fixation.” - Padmasambhava, Liberation Through Seeing With Naked Awareness
"When the Soul fuses with the Inner Master, then it becomes free from Nature and enters into the supreme happiness of absolute existence. This state of happiness is called Nirvana. Nirvana can be attained through millions of births and deaths, but it can also be attained by means of a shorter path; this is the path of “initiation.” The Initiate can reach Nirvana in one single life if he so wants it." - Samael Aun Weor, The Zodiacal Course
"Nirvana is a region of Nature where the ineffable happiness of the fire reigns. The Nirvanic plane has seven sub-planes. A resplendent hall exists in each one of these seven sub-planes of Nirvanic matter where the Nirmanakayas study their mysteries. This is why they call their sub-planes “halls” and not merely “sub-planes” as the Theosophists do. The Nirvanis say: “We are in the first hall of Nirvana or in the second hall of Nirvana, or in the third, or in the fourth, or fifth, or sixth, or in the seventh hall of Nirvana.” To describe the ineffable joy of Nirvana is impossible. There, the music of the spheres reigns and the soul is enchanted within a state of bliss, which is impossible to describe with words." - Samael Aun Weor, The Revolution of Beelzebub