Zbiornik Wody Stary Sobieski

Hidden atop Gallows Hill in Gdańsk, behind an unassuming neoclassical facade, the Old Sobieski Water Tank conceals a vast underground chamber built in 1911. For decades, this reinforced concrete structure — nearly 50 meters in diameter, with two chambers holding 5,000 cubic meters of water — supplied the city with drinking water using gravity alone. Decommissioned in the late 1970s and long inaccessible to visitors, it is now one of the most remarkable points on the Gdańsk Water Supply Trail. Inside, a permanent exhibition tells the story of the city's water — from medieval wells and wooden pipes to modern engineering — while the tank's exceptional acoustics carry even a whisper as an echo for hundreds of steps.