Junctions of cellblocks 8 and 9 at the Eastern State Penitentiary in Philadelphia, Pennsylvania. Mirrors at the left were used by guards to peer around the corner. Now a national historic site left in its dilapidated state, the former prison operated until 1971. Designed by John Haviland and opened in 1829, Eastern State pioneered a revolutionary system of incarceration, dubbed the "Pennsylvania system,” that encouraged separate confinement in which guards were mandated to visit with each inmate three times a day as a form of rehabilitation. Photo by Carol Highsmith, 2019.