Hidden beneath the bustling streets of Istanbul lies a mysterious underground palace — the Basilica Cistern. This ancient marvel is not only a feat of Roman engineering but also a captivating symbol of Istanbul’s layered history. In this post, we’ll explore how the Basilica Cistern was constructed, what its original purpose was, how it evolved over centuries, and the efforts made to preserve its haunting beauty today.
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Construction of the Basilica Cistern
The Basilica Cistern, known in Turkish as Yerebatan Sarnıcı (meaning “Cistern Sinking Into the Ground”), was built in the 6th century during the reign of Byzantine Emperor Justinian I (527–565 AD). It was constructed to provide a secure water reservoir for the Great Palace of Constantinople and surrounding buildings.
The name “Basilica” comes from a public square, or basilica, that once stood above it. The cistern measures about 140 meters long and 70 meters wide, covering an area of nearly 10,000 square meters. It can hold approximately 80,000 cubic meters of water.
The structure is supported by 336 marble columns, each around 9 meters tall, arranged in 12 rows of 28. Many of these columns were repurposed from earlier Roman buildings, which explains the variation in their design and decoration.
Purpose and Function of the Basilica Cistern
The cistern’s primary purpose was to store fresh water that could be used in case of drought or siege. Water was brought from the Belgrade Forest, located nearly 20 kilometers away, via the Valens Aqueduct and other water channels.
It served as a backup water supply for imperial buildings, including the palace and key administrative areas. Despite being underground and hidden from daily life, the cistern played a crucial role in the survival and functionality of ancient Constantinople.
Over the centuries, even as the political powers changed from Byzantine to Ottoman, the cistern continued to provide water, though its usage diminished after the conquest of Constantinople in 1453.
Different Names and Uses Throughout History
Throughout history, the Basilica Cistern has been known by various names. In addition to “Yerebatan Sarnıcı” (the Sinking Cistern), it has also been referred to as the “Subterranean Palace” due to its grand columns and cathedral-like ambiance.
During the Ottoman era, many people forgot its existence until it was rediscovered in the 16th century by scholar Petrus Gyllius, who noticed locals drawing water — and even catching fish — through holes in their basements.
For a long time, it remained largely ignored, only occasionally used by nearby houses and shops. It wasn’t until the 20th century that it was seriously considered a cultural and historical landmark.
Restoration and Preservation Efforts
In the 1960s, the Turkish government undertook the first major restoration project, clearing the cistern of debris and opening it to the public as a tourist attraction. Wooden walkways were installed so visitors could explore its mystical atmosphere without wading through water.
Since then, several restoration phases have taken place, including modern lighting, structural reinforcements, and preservation of the two iconic Medusa heads, which form the bases of two columns and continue to mystify visitors with their origins and placement.
In recent years, the Basilica Cistern has also hosted art exhibitions, concerts, and film shoots, including scenes from Inferno (2016), bringing a fresh cultural layer to this ancient space.
Conclusion
The Basilica Cistern is much more than a water reservoir — it’s a time capsule of Byzantine grandeur, Ottoman mystery, and modern-day fascination. With its dim lights, echoing drops of water, and centuries-old columns, visiting the cistern feels like stepping into a forgotten underworld — one that still breathes with the whispers of ancient empires.
