Basilica Cistern Byzantine Underground Reservoir Istanbul Stone Columns Green And Orange Lighting

A Guide to Istanbul’s Three Monumental Cisterns

Long after Constantinople’s holy relics were sold and its treasures plundered, the mighty underground reservoirs survived. The metropolis once held over 200 cisterns with the oldest and largest clustered in the ancient city center. Many continued to provide water (and fish) for over a millenia, even as their existence disappeared from written records. No one knows how many cisterns remain buried today. Three of the largest have been excavated and opened to the public: the Basilica Cistern (Yerebatan Sarnıcı or Sarayı), the Binbirdirek Sarnıcı (the Cistern of 1001 Columns or Cistern of Philoxenos), and the Cistern of Theodosius (Şerefiye Sarnıcı).

Byzantine Cisterns

Istanbul Basilica Cistern Byzantine Water Reservoir Columns Reflected in Water

For the better part of a millennium, Constantinople had the highest population in the world outside of China – and all those people needed plenty of water. Closed cisterns provided cleaner water than their open-air counterparts, and Roman engineering expertise allowed the Byzantines to construct vast underground structures. They provided permanent hydration to palaces, as well as water for the public during dry spells. Thick walls, usually of brick, were lined with hydraulic plaster to prevent water seeping out. To reduce pressure, corners were curved or beveled. 

Basilica Cistern (Yerebatan Sarayı, Bazilika Sarnıcı)

Istanbul Basilica Cistern Columns And Arches Reflected in Water Byzantine Sixth Century Architecture

The largest and most celebrated cistern in Istanbul is a highlight of any visit to the city. Local nickname Yerebatan Sarayı (Sunken Palace) conveys a sense of its eerie grandeur. The vast scale swallows even the largest crowds, and its nuanced lighting doesn’t detract from the original structure. Perhaps most importantly, it’s the only cistern which hasn’t been completely drained. Although the fish are gone – along with some odors – the swirling water below the walkway provides a constant reminder of the past. It also keeps the space cool and humid.  

The Basilica Cistern takes its English name from the Stoa Basilica which once sat over it. Emperor Justinian had the cistern built underneath during an extensive building campaign after riots destroyed much of the city in 532. Many construction projects at the time recycled pieces from other sites; the 336 nine-meter columns here came from all over the empire. Most famously, one of them features a relief resembling the ‘eyes’ on peacock feathers. It’s believed to have been brought from the Forum of Theodosius I (today’s Beyazıt Square), where similar fragments from a monumental triumphal arch can still be seen. 

Giant Stone Medusa Head Upside Down Supporting Column Basilica Cistern Istanbul

The Byzantines apparently had such a surfeit of sculptures that they could use them as supports for water tanks. Two giant Medusa heads support a  pair of columns nearby. These probably came from the Forum of Constantine, where a third head was found. (The latter has faces on two sides instead of one, and can be seen in the garden of the Istanbul Archaeological Museums.) One head rests sideways, a position which could well have been a way to make everything fit. However, the second head was placed upside-down, for reasons unknown – although tradition says the orientation negates the Gorgon’s petrifying stare.

In spite of neglect, the Basilica Cistern survived multiple earthquakes. Even after the Ottoman Conquest in 1453, it supplied water to Topkapı Palace. Locals were still drawing water and fish from the cavernous well when a Frenchman named Peter Gilles “discovered” it in the mid-16th century. Even until the 1970’s, adventurous visitors often had to be lowered in by their wrists. The site was finally opened as an official monument in 1987.

Istanbul Basilica Cistern Byzantine Sixth Century Reservoir Arches Columns Colorful Lighting

The Basilica Cistern’s lighting slowly shifts in color and intensity to highlight different elements of the space. A series of site-specific sculptures nests discreetly in pockets of space. Regular visiting hours run from 9 a.m. to 6:30 p.m. To avoid crowds, plan to arrive shortly before the cistern opens. Online reservations are not necessary but can reduce waiting time during peak season. Check at the ticket office for information about “Night Shift” tickets featuring concerts and other special events. 

Yerebatan Cd. Alemdar Mah. 1/3. Website: Basilica Cistern.

Binbirdirek Sarnıcı (Cistern of Philoxenos)

This cistern’s Turkish name sometimes leads to confusion: it’s often translated as the Cistern of 1,001 Columns. Technically binbir means 1,001 but it often refers to a number beyond count. Such is the impression given by the 224 columns. For the record, the Binbirdirek held half as much water as the Basilica Cistern – but 40,000 cubic meters is arresting enough.

Binbirdirek Philoxenos Cistern Istanbul Byzantine Underground Reservoir With Multiple Stone Columns

Scholars continue to debate the cistern’s origins. Many identify it with descriptions of the Cistern of Philoxenos, which was built by a Roman senator who arrived with Constantine in the early 300’s. Originally it provided water for his palace, but renovations during Justinian’s reign expanded its supply to the public. The water came from the Valens Aqueduct, portions of which remain in and around the nearby university.

The Binbirdirek’s most striking feature is its columns. Unusually, each pillar consists of two cylinders stacked on top of one another and held together in the middle by a sleeve. (Unfortunately the metal rings replacing the original marble versions look like industrial Band-Aids.) The pieces were quarried from a nearby island, and given unadorned capitals. Most feature a small mason’s mark in Greek lettering.

Over the centuries, the ground level rose nearly five meters. We weren’t clear why the additional sediment was paved over instead of cleared away – perhaps for stability? – but it leaves the columns oddly truncated. Temporary supports and plastic sheeting to catch drips gave the place a ragged air. 

Tickets to the Binbirdirek cost two-thirds the price of the Basilica Cistern, and it doesn’t get huge crowds. (We had it to ourselves on a weekday in May.) However, the slightly lackluster ambiance during the day makes this more of a backup destination. Alternatively, the space often features sound-and-light shows in the evening. At the time of writing, the site does not have a secure website for us to link to. Standard opening hours are 9 a.m. to 5 p.m. every day.

Note that Google Maps shows two structures labeled Binbirdirek Sarnici. The cistern’s entrance is on Imram Öktem Cd., at the end of Mehmet Akif Ersoy Parki. Nearby, a structure in Binbirdirek Parki has a sign for the cistern but does not provide access. 

Cistern of Theodosius (Şerefiye Sarnıcı)

Along with constructing the walls which withstood attacks for a thousand years, Emperor Theodosius II provided his city with another cistern between 428 and 443. Compared to the Basilica and Binbirdirek, it’s relatively tiny. A mere 32 columns support the vaults, although their 10-meter height gives a sense of monumentality. 

Istanbul Theodosius Cistern Entrance With Modern Ceramic Sculpture And Sound And Light Show Billboard
This creature greets visitors at the contemporary entrance to the Cistern of Theodosius.

The Cistern of Theodosius has been incorporated into a contemporary structure, complete with a reflecting pool and a café. Visits automatically include a multimedia presentation with nightclub-style lighting effects. Although we appreciate efforts to connect the site with Turkish heritage, the cistern’s Byzantine architecture gets lost under projections of tile and carpet patterns.

Tickets cost a bit less than the Basilica Cistern. Open daily 9 a.m. to 7 p.m. Piyer Loti Cd. No:2/1. Website: Şerefiyes Sarnıcı.

Further Reading

Istanbul’s giant cisterns have long inspired storytellers. A scene in the James Bond film From Russia with Love was shot in the Basilica Cistern, while a chase in Naomi Novik’s historical fantasy novel The Black Powder War makes inventive use of the columns for navigation in the dark. Dorothy Dunnett’s novel Pawn in Frankincense features a subplot about secret stashes of artifacts and underground connections to other monuments.

Our other posts include A Guide to Istanbul’s Iconic Architecture and A Guide to Sinan’s Ottoman Masterpieces in Istanbul.