USP Allenwood is the high-security penitentiary within the Allenwood Federal Correctional Complex in Union County, Pennsylvania, about 75 miles north of Harrisburg. It opened in 1993, the last of the complex's three institutions to come online after the low- and medium-security prisons were added in 1992 to what had originally been a small minimum-security camp dating to 1952. As the top security tier on the property, USP Allenwood holds inmates who score highest on the Bureau of Prisons' classification system, and its physical setup reflects that — perimeter fencing, guard towers, and more tightly controlled housing than its neighbors on the same campus. Being a high-security penitentiary, it has, like most facilities at this level, seen periodic serious incidents over the years, including inmate violence. It has also held a number of inmates whose cases attracted national attention. For families, the key thing to understand is that USP Allenwood operates under noticeably stricter conditions than the medium- and low-security institutions sharing the Allenwood name and grounds, which generally means more limited contact and stricter visiting procedures, especially for someone transferred in from a lower-security facility.