The story
As you descend the steps into the cool, damp subterranean air of the Basilica Cistern, the bustling streets of Istanbul fade into a distant memory. You are now standing in the Yerebatan Sarnıcı, the Sunken Palace, built by Emperor Justinian in the sixth century. Walk along the raised wooden platforms, following the rhythmic drip of water and the soft, amber glow reflecting off the three hundred and thirty-six marble columns.
Continue toward the very back of the cistern, into the far northwestern corner, where the atmosphere feels a little heavier and the shadows a little deeper. Here, resting in the shallow water at the base of two massive columns, you will find the most enigmatic residents of this underground cathedral: the Medusa heads. Take a moment to look at the first one on your right.
She is positioned completely upside down. Now, look at the one to your left; she rests tilted on her side. Even after fifteen hundred years submerged in the dark, the detail of their features is haunting.
Their hair is a nest of writhing serpents, and their eyes, though carved of stone, seem to hold a chilling, frozen intensity. Historians tell us these colossal marble blocks are examples of spolia—recycled materials taken from older Roman buildings and repurposed to support the weight of the Byzantine Empire. They likely originated from a grand building in the Forum of Constantine.
But the real mystery isn't where they came from; it’s why they were placed this way. In ancient Greek mythology, Medusa was a Gorgon whose gaze could turn any onlooker into solid stone. By placing her head upside down or sideways, the Byzantine builders may have been practicing a form of ancient spiritual insurance.
It is said that the inverted positions were meant to negate her lethal power, ensuring that no one who gazed down into the water would be turned to salt or stone by her reflection. Others suggest a more practical reason: the heads were simply the right height to level the columns when turned on their sides. As you stand here, listen to the silence of the cistern.
It is easy to imagine the superstitious laborers of the sixth century working in the flickering torchlight, perhaps averting their eyes as they lowered these pagan symbols into the mud. Whether they were placed this way out of architectural necessity or to ward off the "Evil Eye," the Medusa heads remain a powerful bridge between the classical world of gods and monsters and the monumental ambition of the Byzantine age. Take a final look into those stony eyes before you turn back toward the light of the modern city above.