The Grey Wardens' prison in the Vimmark Mountains is believed to have been constructed more than a thousand years ago. The original method of construction has been lost to history, but the Warden-Commanders of the Free Marches have maintained the prison's secret through the centuries. The prison is concealed in a great rift in the Vimmark Mountains, far from any easily-traveled mountain passes. The Wardens themselves have spread rumors of banditry and beasts to prevent explorers from approaching.