The Summerland is the name given by Theosophists, Wiccans and some earth-based contemporary pagan religions to their conceptualization of an afterlife.
Emanuel Swedenborg (1688–1772) inspired Andrew Jackson Davis (1826–1910), in his major work The Great Harmonia, to say that Summerland is the pinnacle of human spiritual achievement in the afterlife; that is, it is the highest level, or 'sphere', of the afterlife we can hope to enter.
C.W. Leadbeater, a Theosophist, also taught that those who were good in their previous earthly incarnation went to a place called Summerland between incarnations.
The common portrayal of the Summerland is as a place of rest for souls in between their earthly incarnations. Some believe that after one experiences life to its fullest, and has come to know and understand every aspect and emotion of physical human life (usually after many reincarnations), their deity will allow them to stay in the Summerland for an eternal afterlife, although this belief is not universal among contemporary pagans. Another common element is that the soul has little, if any, recollection of the Summerland once it arrives on the mortal plane again. The Summerland is also envisioned as a place for recollection and reunion with deceased loved ones.
As the name suggests, it is often imagined as a place of beauty and peace, where everything people hold close to their hearts is preserved in its fullest beauty for eternity. It is envisioned as containing wide (possibly eternal) fields of rolling green hills and lush grass. In many ways, this ideology is similar to the Welsh view of Annwn as an afterlife realm. However, the Summerland is also viewed as the place where one goes in the afterlife in traditions of Spiritualism and Theosophy, which is where Wicca got the term.
Summerland is the term mostly synonymous with the Wiccan afterlife. While some non-Wiccan neopagans may hold the Summerland to be their afterlife, the majority of Neopagans who believe in the Summerland are Wiccan. All people, except spirits who remain behind lost and wandering, go to the Summerland, even the wicked. The Summerland will be different for everyone, their own version of Shangri-La. There, they can be reunited with their loved ones, look over those they left behind on Earth, and take time to recuperate from life. Our time in the Summerland is spent processing what we learned, recovering from the hardships, walking with the Lord and Lady and being one with them, and then planning our next life.