The “Sunken Palace” is the largest of several hundred ancient cisterns that lie beneath the city of Istanbul, Turkey. Located just southwest of the Hagia Sophia, the cistern was built by Byzantine Emperor Justinian between 527 and 566 CE.

While the majority of the columns supporting the cistern ceiling are of either Corinthian or Ionic style, at the back of the cistern two columns can be found which instead have Medusa heads for their bases. The decision to use the heads does raise an interesting question of why? Traditionally pictures and sculptures of the Medusa and her sister Gorgons were used to protect important/special places. But, by turning the image upside down or on it’s side, people were instead protected from being turned into stone by the Medusa’s gaze.

Despite having the capacity to store upwards of a 100’000 tons of water, and for centuries acted as the the primary source of water for the neighbourhood – even used to maintain the gardens of the nearby Topkapi palaceOttoman occupation however saw it fall into disuse as they preferred tap water to well water, and gave up using the cisterns once their own plumbing system was installed. In fact by the 1500s no one even remembered it was there. However stories of people getting water by lowering buckets into their basement floors, and occasionally bringing up a fish, caught the attention of French natural scientist Petrus Gyllius, in Instanbul between 1544 and 1547 on behalf King Francis I searching for Byzantine documents, leading him to rediscover the cistern.

Since then it’s gone through repeated restorations, with the most recent, and likely the most extensive of which, being done between 1985 and 1987, it’s absolutely worth the $10TL admissionapproximately $5.50 CDN – that they charge to look around. The Cistern is open daily between 9AM and 5:30PM. Lineups can build quickly, but the Cistern is small enough that it’s able to process groups relatively quickly. Tip: Just remember to have Turkish Lira on hand as they only take local currency.