Ba'ku was an inhabited planet located inside the Briar Patch, in Sector 441, a region of space in the Alpha Quadrant. It was inhabited by the Ba'ku, a humanoid race. The planet's rings produced a unique form of metaphasic radiation that granted those on the surface health and eternal life.
The planet was settled in 2066 by a small group who had fled their star system, fearing that their civilization was headed for self-destruction. Coming to call themselves the Ba'ku, they established an agrarian society without advanced technology. In the mid-23rd century, a group of young Ba'ku who wished to follow the ways of the offlanders were exiled from the planet after a failed attempt to take over their village. They became the Son'a.
In 2154, Dr. Arik Soong planned to relocate his group of Augments to the Ba'ku planet, unaware of its population, in an attempt to hide from Starfleet and the Klingon Empire. He believed the surrounding Briar Patch would make the planet an ideal hiding place, although Malik disagreed. Ultimately, Soong and his augments would never reach the planet. (ENT: "The Augments")
In 2375, there were six hundred Ba'ku living on the planet. As the Briar Patch was now Federation territory, the Son'a colluded with elements of Starfleet to relocate the Ba'ku and collect the metaphasic particles from their planet, which would have destroyed all life on the surface. These plans were thwarted by the crew of the USS Enterprise-E. The Federation Council subsequently halted the relocation plans while a top-level review was conducted. Meanwhile, the Son'a and the Ba'ku began the process of reconciliation.
A rich variety of flora and fauna were found on the Ba'ku planet. Near the Ba'ku village, there were hills and mountains containing veins of kelbonite, which blocked transporter function. The mountains contained caves that could shelter large numbers of people. (Star Trek: Insurrection)
Background information Edit
A further deleted scene would have established that the Federation would ultimately make the Ba'ku planet a protectorate. However, according to the Star Trek: Star Charts ("United Federation of Planets I"), the Ba'ku planet was a Federation member in 2378.
According to Star Trek: Star Charts (p. 62) and Stellar Cartography: The Starfleet Reference Library ("Federation Historical Highlights, 2161-2385"), Ba'ku's primary was a K-class star.
According to the RPG sourcebook Planets of the UFP, the Ba'ku planet's native fauna includes a bird with a bee-like stinger called the jenkaw and a llama-like animal called the e'kar.