Beneath Istanbul’s bustling streets lies a hidden world rich in history and mystery—the Basilica Cistern. Once a vital water source for the city, it now stands as one of Istanbul’s most captivating underground landmarks. With our Basilica Cistern Guided Tour, step into this atmospheric wonder and discover the stories carved into its walls. Walk among the 336 towering columns, illuminated to reveal their intricate beauty, and encounter the legendary Medusa heads that guard the cistern's depths.