Theosophy teaches that Heaven exists, although it is different than the Heaven of orthodox religions.
Heaven has been described as places of rest, while Nirvana has been described as a place of great activity.
-- Different Levels of the Afterlife --
Theosophy teaches of seven (actually 14) levels of the Afterlife.
1. People who were true leaders while on Earth
2. People who felt genuine devotional feelings while on Earth
3. People who engaged in intellectual activity while on Earth
4. People who felt happiness while on Earth
5. (At the Earth's surface) Varied discomfort. Cravings for physical pleasures
6. (Subterranean) Suffering. People who were cruel while on Earth
7. (Subterranean) Only the worst specimens of humanity.
People first gravitate to the level most suited to them, burn off the vibrations at that level, and move up to the next level. When all of the undesireable vibrations have been burnt off, they spend time in Heaven. (People can spend time in Hell, Purgatory, and Heaven in the same afterlife.)*
-- Heaven Above vs. Hell Below --
All of the major religions describe Heaven as above and Hell as below. There is truth to this idea.
Hell actually is a place geographically below the Earth. Heaven is an actual place geographically above the Earth.
“Some ... people tend to hover round their earthly homes [after death], in order to keep in touch with their friends of the physical life and the places which they know; others, on the other hand, have a tendency to float away and to find for themselves, as if by specific gravity, a level much further removed from the surface of the earth. The great majority of the denizens of the astral world spend most of their lives comparatively near to the surface of the physical earth; but as they withdraw into themselves, and their consciousness touches the higher types of matter, they find it easier and more natural than before to soar away from that surface into regions where there are fewer disturbing currents.” (Charles Leadbeater, The Inner Life, page 155)
“The average person passing into the heaven-life, for example, tends to float at a considerable distance above the surface of the earth, although on the other hand some of such men are drawn to our level. Still, broadly speaking, the inhabitants of the heaven-world may be thought of as living in a sphere or ring or zone round the earth. What Spiritualists call the summer-land extends many miles above our heads, and as people of the same race and the same religion tend to keep together after death just as they do during life, we have what may be described as a kind of network of summer-lands over the countries to which belong the people who have created them.
“People find their own level on the astral plane, much in the same way as objects floating in the ocean do. This does not mean that they cannot rise and fall at will, but that if no special effort is made they come to their level and remain there. Astral matter gravitates towards the center of the earth just as physical matter does; both obey the same general laws. We may take it that the sixth sub-plane of the astral is partially coincident with the surface of the earth, while the lowest, or seventh, penetrates some distance into the interior.” (Charles Leadbeater, The Inner Life, page 156)
*Astral atoms are described as having specific gravity, just as physical atoms do. The denser astral atoms are said to “sink” more towards the Earth, and the higher-level, finer astral atoms are said to “rise” to the top of the astral globe that interpenetrates our physical globe. Astral entities (dead people) gravitate to the level equal to the preponderance of their astral atoms, causing the “bad” people to “float” at a lower level, and vice versa.