Hoa Lo Prison is the prison used by French colonists in French Indochina to hold political prisoners, and then in North Vietnam for American prisoners of war during the Vietnam War. Later, it was known to American prisoners of war as "Hanoi Hilton". The architects have preserved enough of the old prison to create the Hoa Lu Prison Memorial Museum. The majority of exhibits here include a horrific array of shackles, whips and other instruments of torture, as well as small French colonial solitary confinement cells and the guillotine used for execution.