The Theodosius Cistern opened again its doors to the public, after an eight-year-long restoration project.
This water tank in Constantinople -Serefiye Sarn, for the Turks- was built on the reign of Emperor Theodosius II (428-443). Its area is about 45 by 25 meters and its roof is based on 32 columns of marble that was specifically transported from the Marmara Island (Prokonnesos or Proikonesos).
During the restoration work, the building was cleaned of mud and ash and the excess water was dealt with. Steel rings reinforced all 32 columns to prevent future damage, and steel connecting rods were placed for further structural support of the cistern. No further reinforcement of the walls and the floor was necessary.
Parts of the vaults that had collapsed were replaced with similar, but distinct materials. Missing bricks on the walls were replaced with similar ones, but they were placed 5 cm deeper to indicate that they were additions. The cracks in the walls were covered with special plaster and the capillary cracks in the columns by epoxy injection.
All interventions are absolutely visible to the visitors to enable them to discover the various levels of constructional intervention in the building.
The main façade of the cistern has now an additional steel and glass structure to provide room for two foyers and offices. Theodosius Cistern functions as a museum and can receive visitors again.