Basilica Cistern
Introduction
The Basilica Cistern, also known as the Yerebatan Sarnıcı, is an ancient subterranean water reservoir located in Istanbul, Turkey. It is one of the most significant and well-preserved examples of Byzantine architecture and engineering. Constructed during the reign of Emperor Justinian I in the 6th century, the cistern was designed to supply water to the Great Palace of Constantinople and other buildings in the area. The Basilica Cistern is renowned for its vast size, intricate column designs, and the mysterious Medusa heads that adorn its interior.
Historical Background
The construction of the Basilica Cistern began in 532 AD, following the Nika Riots, which devastated much of Constantinople. Emperor Justinian I commissioned the cistern as part of a broader effort to rebuild and fortify the city. The cistern was built beneath a large public square, the Stoa Basilica, which was a bustling center of commerce and law during the Byzantine period.
The cistern's primary function was to store water transported via aqueducts from the Belgrade Forest, approximately 19 kilometers north of the city. This water supply was crucial for sustaining the population of Constantinople, especially during sieges or droughts. The cistern continued to serve as a vital water source throughout the Byzantine and Ottoman periods.
Architecture and Design
The Basilica Cistern is an architectural marvel, measuring approximately 138 meters in length and 65 meters in width, with a capacity to hold around 80,000 cubic meters of water. The ceiling is supported by 336 marble columns, each standing 9 meters tall, arranged in 12 rows of 28 columns. The columns are primarily of the Corinthian and Ionic orders, showcasing the artistic influences of the time.
The columns were repurposed from earlier Roman structures, a common practice in Byzantine architecture, which adds to the cistern's historical significance. The bases of two columns feature the enigmatic Medusa heads, which are believed to have been placed in their current positions—one upside down and the other sideways—to negate the power of the Gorgon’s gaze or simply as a practical solution for column height adjustment.
Engineering and Hydraulics
The engineering of the Basilica Cistern reflects the advanced understanding of hydraulics possessed by Byzantine engineers. Water was channeled into the cistern through a series of aqueducts, including the Valens Aqueduct, which was a major feat of engineering in its own right. The cistern's walls are constructed of brick and mortar, with a thickness of approximately 4 meters, ensuring its durability and water-tightness.
The floor of the cistern is lined with a thick layer of waterproof mortar, which has contributed to its preservation over the centuries. The cistern also features a sophisticated system of sluice gates and channels that allowed for the regulation of water levels and distribution to various parts of the city.
Cultural and Historical Significance
The Basilica Cistern holds immense cultural and historical significance, not only as a testament to Byzantine engineering but also as a symbol of the city's resilience and adaptability. It has been featured in numerous literary works, films, and television series, highlighting its enduring allure and mystery.
During the Ottoman period, the cistern fell into disuse as the city developed alternative water supply systems. However, it was rediscovered in the 16th century by the scholar Petrus Gyllius, who documented its existence and significance. Today, the cistern is a popular tourist attraction, offering visitors a glimpse into the grandeur of Byzantine Constantinople.
Preservation and Restoration
The preservation of the Basilica Cistern has been a priority for both Turkish authorities and international organizations. Restoration efforts have focused on maintaining the structural integrity of the cistern, as well as conserving its unique architectural features. Modern lighting and walkways have been installed to enhance the visitor experience while ensuring the protection of the site.
The cistern's microclimate, characterized by high humidity and stable temperatures, has played a role in its preservation. However, ongoing monitoring and maintenance are essential to address issues such as water infiltration and biological growth that could threaten the site's integrity.