Lucifer's Cage is a special part of Hell, designed by God to imprison Lucifer after he rebelled against Heaven, twisted a human soul into the first demon and corrupted the Garden of Eden. It is described as the deepest, most heavily protected part of Hell. It currently holds the Archangel Michael, as well as Michael's substitute vessel Adam Milligan. Sam Winchester also spent some time in the Cage, but was "rescued" by Castiel. He was unable to raise Sam with his soul, so it spent well over a year (more than 120 years in Hell time) in the Cage being tortured by Lucifer until Death finally retrieved it.