Facility 4028

Facility 4028 was a secret Federation prison in the Ayala system, in the early 25th century. It was run by holographic personnel, led by a holographic warden simply called The Warden. The facility held the Female Changeling until her release in 2409. 

In 2410, a group of Augments from the Children of Kahn broke into the facility to steel the Soong-type android parts for Lore. While there, they had planned to break Amar Singh out, but a disagreement with him led the Augments to leave him behind. With Kayl's mind-reading ability, she was able to determine, from Amar, that the Augments had escaped to an abandonned Klingon base in the Briar Patch. The quickly made way and confronted the group. Upon learning Lore had no real intention in helping them, the Augments made haste to escape, leaving Lore partially assembled, behind, for the crew of the Phoenix-X. ("Myths and Lore, Part I")