This is a wonderfully rich historical site in Boise that is also known as Idaho Territorial Prison. Located at the Old Idaho Penitentiary Road it was built in 1870. The prison is located east of Boise and was built even before the Territory of Idaho was a decade old. Beginning as a single cell house the Penitentiary structure grew into several buildings, which were surrounded by a high sandstone wall – the stone actually quarried by resident convicts at the prison. Those same convicts also completed the rest of the construction of the prison. The Old Idaho Penitentiary State Historic Site was placed on the National Register of Historic Places in 1973. Currently, the Site houses several museums and an arboretum. It makes an educational and historically rich field trip or touring spot.