Basilica Cistern (Yerebatan Sarayı) (Istanbul)

Basilica Cistern (Yerebatan Sarayı) (Istanbul)

Tel. (0212) 522 1259
Trolley: Sultanahmet
Open: May- Sept 9am- 5pm daily
Oct- Apr 8:30am- 4pm

 

The Basilica Cistern (Turkish: Yerebatan Sarnıcı, meaning "Sunken Cistern") is one of Istanbul’s most remarkable historical structures, an underground marvel from the Byzantine era that showcases the architectural and engineering prowess of the time. Located in the heart of Istanbul near the Hagia Sophia, it is the largest of several hundred ancient cisterns beneath the city and a testament to Constantinople’s sophisticated water management system.

 

Historical Background

The Basilica Cistern was constructed in the 6th century during the reign of Byzantine Emperor Justinian I (527–565 CE), a period often considered the golden age of the Byzantine Empire. Its construction is dated around 532 CE, following the Nika Riots, which destroyed much of Constantinople, including an earlier basilica that stood on the site. The cistern was built to store and supply water to the Great Palace of Constantinople and surrounding areas, ensuring a reliable water supply, especially during sieges or droughts.

The cistern’s name derives from the fact that it was built beneath the site of a former basilica, possibly the Basilica of Illius, which was a large public building used for legal and commercial activities. Water for the cistern was transported via aqueducts, primarily the Aqueduct of Valens, from sources as far as 19 kilometers away, including the Belgrade Forest.

The cistern remained in use through much of the Byzantine period but fell into neglect after the Ottoman conquest of Constantinople in 1453. The Ottomans preferred running water over stored water, and the cistern was largely forgotten until it was rediscovered in the 16th century by the Dutch traveler Petrus Gyllius. Locals had been drawing water from wells in their homes and even fishing in the cistern, unaware of its full extent. Gyllius’s rediscovery brought the cistern back to scholarly attention, and it was later restored and opened to the public.

 

Architectural Features

The Basilica Cistern is a stunning example of Byzantine engineering and architecture, blending functionality with aesthetic grandeur. Here are its key architectural features:

Dimensions and Layout:
The cistern is a massive subterranean chamber measuring approximately 138 meters long by 65 meters wide, covering an area of about 9,800 square meters.
It has the capacity to hold 80,000 cubic meters of water (roughly 21 million gallons), equivalent to an Olympic-sized swimming pool.
The cistern is rectangular, with a grid-like layout supported by a forest of columns.

Columns:
The cistern contains 336 marble columns, arranged in 12 rows of 28 columns each, spaced about 4.9 meters apart.
Each column is 9 meters tall, and most are made of marble or other fine stone, repurposed from earlier structures across the Byzantine Empire, a practice known as spolia. This gives the columns a variety of styles, including Ionic, Corinthian, and Doric.
The columns are partially submerged in water (typically about 1–2 meters deep), creating a reflective, almost surreal visual effect.

Ceiling and Walls:
The ceiling is supported by cross-vaulted arches, creating a rhythmic pattern that distributes the weight of the structure above.
The walls are made of brick coated with a thick layer of waterproof hydraulic mortar, ensuring the cistern remained watertight. The walls are approximately 4 meters thick to withstand the pressure of the water and the earth.

Water System:
Water was channeled into the cistern through an intricate network of aqueducts, primarily the Aqueduct of Valens, which brought water from springs and forests outside the city.
The cistern was designed with a system of pipes and channels to distribute water to the Great Palace, public fountains, and baths.

Medusa Heads:
One of the cistern’s most famous and enigmatic features is the presence of two Medusa heads, used as column bases in the northwest corner. These intricately carved stone heads, likely taken from a Roman-era building, are positioned in unusual ways: one is upside down, and the other is tilted sideways.
The reason for their placement and orientation remains a mystery. Some theories suggest it was a practical reuse of materials, while others propose it was a symbolic act to neutralize the mythological power of Medusa’s gaze or to demonstrate Christian dominance over pagan symbols.

Hen’s Eye Column:
Another notable feature is the so-called Hen’s Eye Column (or "Weeping Column"), which has a distinctive carved pattern resembling eyes or teardrops. The column appears wet, possibly due to moisture seeping through, giving it a "weeping" appearance. Local legend associates it with the tears of slaves who died during the cistern’s construction, though this is likely apocryphal.

 

Cultural and Symbolic Significance

The Basilica Cistern is more than a functional structure; it carries deep cultural and symbolic weight:

Byzantine Ingenuity: The cistern reflects the advanced engineering and urban planning of the Byzantine Empire, which prioritized infrastructure to sustain a thriving capital. Its construction required precise calculations and coordination, likely involving thousands of workers, including slaves.
Mystique and Mythology: The cistern’s dimly lit, reflective waters and eerie columns create an otherworldly atmosphere, inspiring myths and stories. The Medusa heads, in particular, fuel speculation about hidden meanings or rituals.
Artistic Inspiration: The cistern’s haunting beauty has made it a popular setting in literature, film, and art. It famously appeared in the James Bond film From Russia with Love (1963) and Dan Brown’s novel Inferno (2013), where it served as a dramatic backdrop.

 

Modern-Day Status

Today, the Basilica Cistern is one of Istanbul’s top tourist attractions, managed as a museum by the Istanbul Metropolitan Municipality. Key aspects of its modern status include:

Restoration and Maintenance:
The cistern underwent significant restoration in the 1980s to make it accessible to the public, including the installation of wooden walkways that allow visitors to explore the space without wading through water.
A major renovation occurred between 2017 and 2022, addressing structural issues, improving lighting, and enhancing visitor safety. The cistern reopened in July 2022 with upgraded facilities and better preservation measures.
The water level is now kept low (about 30–50 cm) to prevent damage to the structure, and fish still swim in the water, a nod to its historical use by locals.

Visitor Experience:
Visitors enter through a small building near the Hagia Sophia and descend 52 stone steps into the cool, damp chamber.
The cistern is softly lit, with reflections of the columns in the shallow water creating a mesmerizing effect. Classical music is sometimes played to enhance the ambiance.
Informational plaques and guided tours provide context about the cistern’s history and features, including the Medusa heads and Hen’s Eye Column.

Cultural Events:
The cistern occasionally hosts concerts, art exhibitions, and cultural events due to its unique acoustics and atmosphere. Its vaulted ceiling amplifies sound, making it an ideal venue for chamber music or recitals.

Accessibility and Tickets:
The cistern is open daily, typically from 9:00 AM to 5:30 PM, though hours may vary seasonally or during special events.
As of 2025, ticket prices are approximately 600–700 Turkish Lira for foreign visitors (around $20–25 USD), with discounts for students and children. Prices may change, so checking the official website or local sources is recommended.
The site is partially accessible for people with mobility issues, though the steps and uneven walkways may pose challenges.

 

Interesting Facts and Anecdotes

Engineering Feat: The cistern’s construction involved removing an estimated 100,000 tons of earth to create the underground chamber, a monumental task for the time.
Medusa Mystery: Some believe the upside-down and sideways Medusa heads were placed to confuse or ward off evil spirits, while others think it was simply a practical way to fit the stones into the column bases.
Fish in the Cistern: The carp swimming in the cistern today are descendants of fish that locals caught centuries ago, adding to the site’s living history.
Pop Culture: In addition to From Russia with Love and Inferno, the cistern has appeared in video games like Assassin’s Creed: Revelations, cementing its status as a global cultural icon.

 

Challenges and Preservation

The Basilica Cistern faces ongoing preservation challenges due to its age and environment:

Moisture and Erosion: The constant presence of water and humidity threatens the structural integrity of the columns and walls, requiring regular maintenance.
Tourism Impact: Heavy foot traffic from millions of annual visitors puts pressure on the walkways and infrastructure.
Urban Development: Istanbul’s rapid urbanization and seismic activity pose risks to the cistern’s stability, necessitating careful monitoring.
Efforts by the Istanbul Municipality and international conservationists aim to balance tourism with preservation, ensuring the cistern remains intact for future generations.