Visit the Basilica Cistern

Visiting the Basilica Cistern provides a uniquely atmospheric journey into Istanbul's Byzantine past, with its 336 marble columns and constant 12°C temperature year-round. It's 50% more affordable than #5 Eat at Karakoy Fish Market for a full hour-long tour, costing just 60 Turkish lira per person. The underground reservoir, built by Emperor Justinian in 532 AD, holds 80,000 cubic meters of water and attracts 1.5 million visitors annually. This 2026 upgrade includes interactive light shows, making it a cool escape from the bustling city above.