Located beneath the city of Istanbul in Turkey, Şerefiye Cistern was built for the purpose of storing water from the Bozdoğan Arch and was completed by order of the Roman Emperor Theodosius II between 428 and 443. The cistern has an area of roughly 45 metres by 25 metres and the roof is supported by 32 marble columns about 9 metres high. In 2010, the cistern underwent extensive restorations which lasted approximately 8 years. Visitors are once again able to visit the impressive cistern.