In current U.S. military parlance, a prison for those who may have valuable intelligence to offer, or who have inherent military or political significance. An example is former Iraqi president Saddam Hussein, as well as senior members of his regime. Other prisoners of these sites include members of the Al-Qaida terrorist organization, captured during the so-called War on Terrorism.
Recent examples of such sites are Guantanamo Bay in Cuba and Abu Ghraib prison in Iraq.