Sultan Cistern
Sultan Cistern is located near the southeast corner of the Cistern of Aspar near Yavuz Selim Mosque. Its date and identity are uncertain, but it seems to date to the 6th or 7th century. For a period of time, the cistern was used by spinners in the production of textiles. It has recently been converted into a privately owned restaurant, Sultan Sarnıç (Sultan Cistern) Restaurant.
It has a rectangular plan, measuring around 29 x 19 meters. The vaulted roofing is supported a total of 28 columns (4 rows with 7 seven columns). These columns have Corinthian capitals and Ionic imposts. One of the columns has a relief with a cross which is 50 cm long. Although some columns are granite, most of them are made marble (with a diameter ranging from 50 to 55 cm) and rest on Attic bases. The walls of the cistern are 2.8 meters thick and are lined with hydraulic plaster. The cistern rises above the ground level. It is unclear if it was originally connected to the nearby open cistern of Aspar.
From the Nicholas V. Artamonoff Collection

Plan by Forchheimer & Strzygowski
Sources
İstanbul'da Bizans Dönemi Sarnıçlarının Mimari Özellikleri ve Kentin Tarihsel Topografyasındaki Dağılımı by Kerim Altuğ
Die Byzantinischen Wasserbehalter von Konstantinopel by Forchheimer & Strzygowski
Istanbul'da Bizans Samıçları 2 by E. Yücel
Resources
Byzantine Cisterns of Constantinople Photo Album (Byzantine Legacy Flickr)