The planet Ba'ku was a M-class planet located in the Briar Patch, in Sector 441. It was the location of a Ba'ku colony, and was characterized by a unique effect caused by the planet's rings that cause the planet's inhabitants not to age.
Ba'ku was a ringed planet, the rings themselves being saturated with metaphasic radiation. The planet was home to a Ba'ku settlement, established in 2066 by a group of approximately 600 of the Ba'ku, fleeing their homeworld for fear of their race's self-destruction. The planet's radiation allowed the inhabitants to live extended life spans, In the late 23rd century, a group of the Ba'ku, disillusioned with the settlement's ways, left the planet, and became the Son'a.
In 2375, an attempt by the Son'a – led by Ahdar Ru'afo, and assisted by Starfleet officers under Matthew Dougherty – to strip the planet of its metaphasic particles and to forcefully relocate the Ba'ku to another planet, was stopped by the actions of Jean-Luc Picard and the crew of the USS Enterprise-E.
There are many species of animal life on the Ba'ku planet, several of which can be seen in a Ba'ku children's book. These species' names are unknown, but pictures have been seen of a six-legged turtle-like animal, a polar bear-like animal, an animal that resembles an ancient Earth pterodactyl, and a Ba'ku butterfly.