Well, Jhananda. I've always wondered about the realms of Samsara. This list is typical of Theravadan teachings which is supposedly based on the suttas. Do you agree with this description?
The realms of existence are customarily divided into three distinct "worlds" (loka), listed here in descending order of refinement:
The Immaterial World (arupa-loka). Consists of four realms that are accessible to those who pass away while meditating in the formless jhanas.
loca is better translated as "domain of existence," or "dimension." However, I do agree that they are accessed through the 4 immaterial attainments (not arupa jhana, but ayatana-samadhi).
The Fine-Material World (rupa-loka). Consists of sixteen realms whose inhabitants (the devas) experience extremely refined degrees of "bliss" not "pleasure."
These realms are accessible to those who have attained at least some level of jhana and who have thereby managed to (relatively) dismantle the fetters. They are said to possess extremely refined bodies of pure light.
The highest of these realms, the Pure Abodes, are accessible only to those who have attained to "non-returning," the third stage of Awakening. The Fine-Material World and the Immaterial World together constitute the "heavens" (sagga).
The Sensuous World (kama-loka). Consists of eleven realms in which experience — both pleasurable and not — is dominated by the five senses. Seven of these realms are favorable destinations, and include our own human realm as well as several realms occupied by devas. The lowest realms are the four "bad" destinations, which include the hell realms. Leave the animals out, because humans are clearly below animals.