Basilica Cistern and the Mysterious Medusa Heads

The Basilica Cistern is considered one of the most important historical buildings in Istanbul. Dating back to the Byzantine Empire, this large and impressive structure was built to meet the city’s water needs.

Today, it attracts the attention of tourists and local visitors with its historical and cultural value as well as its architectural features.

Basilica Cistern history

The Basilica Palace was built in 532 by the Byzantine Emperor Justinian I. The cistern, which was one of the city’s most important water reservoirs at the time it was built, played an important role in meeting Istanbul’s water needs. This gigantic structure was used to store and distribute the water brought to the city from the Valens (Bozdoğan) Arch and other water structures.

The water could reach here through the arches built in the Belgrade Forest, about 22 kilometers away. These gently sloping arches, an engineering marvel of the period, were gravity-fed to the water collection pools in Constantinople, where it was collected and then distributed to the cisterns through underground tunnels. The public could also draw water from the cisterns and use it by using the pump pumps in their gardens or on the streets.

Things to do in Sultanahmet
Things to do in Sultanahmet

Basilica Cistern is called Basilica Cistern in English because there used to be a basilica on or around the cistern. It is also known as the Basilica Cistern because of the difference in size and the splendor of the columns. The Byzantine and Roman Empires used these cisterns to survive possible wars.

Yerebatan Palace has undergone various repairs and restorations throughout history. The cistern, which was also used during the Ottoman Empire, was then abandoned for a while and rediscovered by Petrus Gyllius in the 16th century.

Today, the water from the Basilica Cistern is no longer used to meet the city’s drinking water needs. In 1987, after a large-scale restoration, the Basilica Cistern was opened to touristic visitors.

Istanbul Yerebatan Sarnici Sutunlari
Istanbul Yerebatan Sarnici Suyu

The cistern is still full of water and visitors can discover the beauty of this huge structure by walking on wooden paths that walk on the water inside the cistern. In this way, the cistern offers visitors an unforgettable experience, not only for its historical and architectural value, but also for its relationship with water.

Architectural features

The Basilica Cistern attracts attention with its enormous dimensions and impressive architecture. There are 336 columns in total and they are placed in 12 rows.

The columns were generally obtained from the ruins of ancient buildings and are largely decorated in Corinthian style. The ceiling of the cistern is made of bricks and mortar to keep the water inside.

The story of the Medusa head statue in the Basilica Cistern

One of the most intriguing and mysterious features of the Basilica Palace is the two Medusa heads in the cistern. Medusa is an eerie creature from Greek mythology, known for the snakes on her head. Those who look at Medusa are famous for turning to stone.

Mysterious Medusa heads
Mysterious Medusa heads
Istanbul Yerebatan Sarnici Medusa Basi Hikayesi

The Medusa heads in the Basilica Cistern were placed at the base of two columns in the westernmost corner of the cistern, on the blocks supporting the columns. Interestingly, one of these heads is positioned upside down and the other on its side. Although there is no definite information about why and for what purpose the Medusa heads were used here, there are some theories.

According to one theory, the Medusa heads were obtained from the remains of ancient structures used to build the cistern and were added as an architectural ornament to the structure. Another theory suggests that the Medusa heads were placed here to prevent evil spirits and contamination of the water in the cistern.

Today, the water level of the cistern is kept below the walking platform. In the absence of this walking platform, the cistern used to be navigated by boat. In Dan Brown’s novel Inferno (Inferno), which was adapted into a movie, the scene of the Basilica Palace takes place.

Istanbul Yerebatan Sarnici Nerede

You can see an example of traveling by boat in the 1963 James Bond movie. Tourists throw coins into the water, which looks like a pool with various fish in it, supposedly to make their wishes come true. You can see the coins in the pool.

Basilica Water Balance

The Basilica Palace Water Scale is a historical measuring instrument located inside the cistern in Istanbul and used to measure the water level of the cistern. Since the construction of the cistern, this scale was used to keep the water level under control and to drain the water out or provide additional water when necessary.

The spirit level was placed on a column inside the cistern and was designed in such a way that the scale would move according to the rise and fall of the water level. In this way, the flow of water could be regulated by recognizing when the water level in the cistern was low or when there was too much water.

Spirit level
Spirit level
Million stone
Million stone

The Basilica Palace Water Scale is a feature that draws attention with its historical and architectural value as well as the functionality of the cistern. Visitors to the cistern can also see this historical scale and better understand how important the cistern was in terms of water management in ancient times.

Things to know before visiting

There are some things to consider and take into account when visiting this historical building.

  1. The temperature and humidity inside the cistern is high, so it is a good idea to wear comfortable clothes and bring water with you.
  2. Since there may be puddles on the floor of the cistern, it is important to wear non-slip and comfortable shoes.
  3. You can combine your visit to the Basilica Palace with other historical and tourist attractions in the area. Hagia Sophia, Topkapi Palace, Blue Mosque, Blue Mosque, Grand Bazaar and Archaeological Museums are all in close proximity to the cistern. In this way, you can visit important places in the historical peninsula of Istanbul in a single day.
  4. Do not neglect to see the Medusa heads in the cistern. These unique artifacts are among the most interesting and prominent features of the cistern.

Istanbul Yerebatan Sarnici Heykelleri
Istanbul Yerebatan Sarnici Gorulecek Seyler

What are the entrance fee and visiting hours of the Basilica Cistern?

Entrance here is paid and students can enter with a discount. You can visit between 09:00 – 22:00 every day of the week, including Monday. You can check the website for up-to-date information.

  • Since Basilica Palace is not affiliated to the Ministry of Culture, Museum Card is not valid. You need to visit the cistern by paying the entrance fee.
  • Both credit cards and cash in Turkish Lira are accepted for entrance fee payments. Payment cannot be made in foreign currency.
  • You can buy entrance tickets to the Basilica Cistern online via Passo. In this way, you can realize your visit without waiting in the ticket line.
  • Visitors who buy discount tickets online are required to show ID at the entrance. Be ready to show your ID for your discount ticket to be valid.
  • Purchased tickets are valid for one entry on the same day and are non-refundable. Please note this when planning your visit.
  • Visitors over 65 years of age are admitted free of charge. It is important for visitors in this age group to have their ID with them.

How to get to the Basilica Cistern?

The cistern, which is among the places to visit in the historical peninsula, is located in the historical peninsula of Istanbul and transportation is quite easy. The most convenient options for those who want to go by public transportation are tram and metro.

  • By getting off at Sultanahmet stop on the T1 Kabataş-Bağcılar tram line, you are only a few minutes walk from the cistern.
  • On the M2 Yenikapı-Hacıosman metro line, you can get off at the Vezneciler stop and walk to the cistern in about 10-15 minutes.
  • If you are coming from Kadıköy, Üsküdar, reach Eminönü and take the tram. You can get off at Sultanahmet tram stop and walk to the cistern.

For those who prefer to go by taxi or private car, it is important to pay attention to Istanbul traffic. Since it may be difficult to find a parking space around the cistern, it may be more convenient to reach the cistern on foot by using the nearby parking lots.


All in all, the cistern is the perfect place to explore the historical and cultural richness of Istanbul. The cistern’s architectural structure, features such as the water scales and the mysterious Medusa heads offer visitors an unforgettable experience. Visiting the Basilica Cistern provides an opportunity to learn more about the history and architecture of the city.