The Akritirian maximum security detention facility was a space station used as a prison, operated by the Akritirian government, located somewhere in their space.
The prison held close to fifty inmates in a single chamber, with no access points save for a single small tunnel, the "chute", sealed by a force field. The chute lead to an airlock on the exterior, where ships docked periodically to deposit food and new prisoners. The fact that the prison was in space was largely unknown to the inmates, most of whom believed that the prison was three hundred meters underground.
Life in the prison was savage. Inmates lived in squalor, and were fitted with a synaptic stimulator called a clamp which induced them to kill each other by inducing edginess and jumpiness, leading to people becoming aggressive and turning crazy.
In 2373, USS Voyager senior officers Lieutenant Tom Paris and Ensign Harry Kim were sent to this facility after being falsely convicted of a bombing on Akritiri. They were eventually rescued by a team from Voyager, led by Captain Kathryn Janeway and Lieutenant Tuvok. (VOY: "The Chute")
The Akritirian facility was designed by Rick Sternbach. The original layout featured six call blocks or station "arms", though the producers had it reduced to three. [1]
According to the Star Trek: Star Charts (p. 86), the Akritiri Prison Satellite was located in interstellar space and not in the Akritiri star system.