Holmesburg Prison is part of the City of Philadelphia Prison System. Built in 1896 and in continuous use until 1995, the facility is located at 8215 Torresdale Ave in the Holmesburg section of Philadelphia, Pennsylvania. It was the site of a controversial decades-long dermatological, pharmaceutical, and biochemical weapons research projects involving testing on inmates. The prison is also notable for several major riots in the early 1970s as well as a report released in 1968 of the results of an extensive two-year investigation by the Offices of the Philadelphia Police Commissioner and the District Attorney of Philadelphia documenting hundreds of cases of the rape of inmates. The 1998 book Acres of Skin: Human Experiments at Holmesburg Prison, by Allen Hornblum, documents clinical non-therapeutic medical experiments on prison inmates at Holmesburg.