The Sultan’s amazing water supply

One of the best places to visit in Istanbul on a hot day is the Basilica Cistern. An underground water tank may not sound much – but the cool, cavernous depths of this immense Roman chamber are incredibly atmospheric.

While our Istanbul City Bus Tour can’t take you underground, you can hop on or hop off nearby to submerge yourself in this cistern’s fascinating history.

Why is the Basilica Cistern here?

This cathedral-size cistern was built during the reign of Emperor Justinian I in 532 AD to supply water to the Great Palace. It stores up to 80,000 cubic metres (2,800,000 cubic feet) of water, delivered via 20 kilometres (12.4 miles) of aqueducts from a reservoir near the Black Sea.

When the Byzantine emperors moved away from the Great Palace, the Basilica Cistern, Istanbul was forgotten. But an inquisitive Frenchman, Peter Gyllius, rediscovered it in the 1500s after hearing stories of locals drawing up fresh water and even fishing from holes in their cellars.

Take the underground

As you walk along its raised wooden platforms, spot fat carp swimming under your feet and feel drips of cool water from the vaulted ceiling. You’ll be taken back to a lost age.

Other interesting facts about Basilica Cistern, Istanbul

  • The vaulted brick ceiling is held up by 336 30-foot (9-metre) pillars taken from nearby Roman ruins
  • The Basilica Cistern holds an artificial freshwater lake the size of two football fields
  • It’s the largest of several hundred ancient cisterns that lie beneath the city of Istanbul
  • The Basilica Cistern is also known as ‘the Sunken Palace’