The mythical paradise at the centre of the galaxy that Sybok sought in Star Trek V, where an imprisoned being pretended to be God.
Sha Ka Ree is a legendary planet said to lie at the centre of the galaxy, behind an energy field called the Great Barrier. Versions of the same myth of a paradise and source of creation exist in the cultures of many peoples, including Vulcans, Klingons and humans.
In Star Trek V: The Final Frontier, Spock's half-brother Sybok takes hostages on Nimbus III to lure a starship, then seizes the Enterprise-A and takes it through the Great Barrier. The planet beyond turns out to be real, and a powerful being appears there, claiming to be God and demanding the starship.
Kirk questions why such a being would need a ship, and it attacks him. Sybok realises he has been deceived and sacrifices himself to hold it back. A Klingon Bird-of-Prey, at Spock's request, fires on the being, which turns out to be imprisoned on the planet, and the crew escapes.