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We bet you didn’t know these facts about the Basilica Cistern

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The Basilica Cistern, also known as the Yerebatan Sarayı or ‘Sunken Palace’, is an ancient underground water reservoir in Istanbul, Turkey. The cistern was designed to store water for the Great Palace of Constantinople and surrounding buildings, ensuring a reliable water supply for the city during drought or siege. With nearly 1,500 years of history and witnessing the rise and fall of the Roman, Byzantine, Latin, and Ottoman empires, the Basilica Cistern holds immense historical significance.

Before visiting this popular landmark, familiarize yourself with these fascinating facts to fully appreciate its rich heritage.

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Interesting facts about Basilica Cistern


1. Location and proximity to historical landmarks

The Basilica Cistern is strategically located on Yerebatan Cd. Street, just southwest of the iconic Hagia Sophia. Its proximity to the Million Stone, considered the "zero point" of the Byzantine Empire, highlights the cistern's historical significance.

2. Rediscovery by Petrus Gyllius

The Basilica Cistern fell into disrepair and was largely forgotten until 1545, when it was rediscovered by Petrus Gyllius, a Dutch traveler and scholar. Gyllius was exploring the area when local residents mentioned an underground water source accessed through their basements. Upon investigation, he found the magnificent cistern and documented his findings.

3. The Hen's Eye Column and wish-making hole

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One of the cistern's most intriguing features is the ‘Hen's Eye’ column, named for the unique teardrop patterns carved into its surface. This column is believed to possess wish-granting powers, and people often insert their finger into a small hole in the column, making a wish as they rotate their hand 360°.

4. Featured in popular films

The Basilica Cistern has been featured in several iconic movies, including the 1963 James Bond film From Russia with Love and the 2016 thriller Inferno, based on Dan Brown's novel. In From Russia with Love, Sean Connery's Bond rows a boat through the cistern's waters during a chase scene. Inferno showcases the cistern's mysterious atmosphere, with Tom Hanks' character, Robert Langdon, uncovering clues within its depths.

5. The largest of Istanbul's many cisterns

Istanbul is home to hundreds of ancient cisterns, but the Basilica Cistern stands out as the largest and most impressive. With a capacity of approximately 100,000 cubic meters, it dwarfs other cisterns in the city.

6. Thick walls and waterproof mortar

The Basilica Cistern's walls, constructed from brick, are 5 meters thick. To ensure the structure remained watertight, Khorasan mortar, also known as Brick Powder Mortar, was applied to the floor and walls. This special mortar, made from a mixture of brick dust, lime, and sand, was a crucial component in preventing water leakage, allowing the cistern to function effectively for centuries.

7. Construction time and labor

The construction of the Basilica Cistern was a massive undertaking that spanned 38 years. Approximately 7,000 slaves were employed in the building process.

8. The mysterious source of water

The water inside the Basilica Cistern comes from a mysterious source, believed to be connected to the Eğrikapı Water Distribution Center, nearly 20 kilometers away. This elaborate system of aqueducts and underground channels supplied the cistern with a constant flow of fresh water. The cistern's floor is slightly sloped, allowing water to collect in a central pool, which could be accessed through a well.

9. The Crying Column

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Among the 336 columns in the Basilica Cistern, one stands out for its unique appearance. Known as the ‘Crying Column’ or ‘Weeping Column’, this pillar features carvings resembling eyes and tears. The origins of these carvings remain a mystery, with some speculating they represent the hundreds of slaves who died during the cistern's construction.

10. Basilica Cistern has survived many earthquakes

The Basilica Cistern's resilience is a testament to the skill and ingenuity of its builders. Despite 22 earthquakes that have shaken Istanbul over the centuries, the cistern has remained largely intact. Using flexible materials like brick and mortar, combined with the structure's underground location, has helped it withstand seismic activity.

11. Placement of the Medusa Heads

Two massive Medusa heads, carved from marble, support two columns at the far end of the cistern. These impressive sculptures, believed to date back to the Roman period, have been placed sideways and upside down, leading to much speculation about their origins and positioning. Some theories suggest they were placed in this manner to negate Medusa's mythical power to turn onlookers to stone, while others believe they were simply repurposed from another building.

Basilica Cistern Facts