Marmara Prison (Turkish: Marmara Cezaevi) or officially Marmara Penitentiaries Campus (Turkish: Marmara Ceza İnfaz Kurumları Kampüsü) formerly Silivri Prison is a high-security state correctional institution complex in the Silivri district of Istanbul Province in Turkey. Established in 2008, it is the country's most modern and Europe's largest penal facility. The prison complex is located 9 km (5.6 mi) west of Silivri on the highway E84, which connects the highway D.100 to the European Motorway O-3 (E80). In 2022, the prison's name was changed to Marmara Prison.