Poppenbüttler Schleuse, Lock in Poppenbüttel, Hamburg, Germany

Poppenbüttler Schleuse is a water control system on the Alster River in Hamburg that uses mechanical gates to regulate water levels between different river sections. The structure allows boats to navigate between different elevations while managing water flow throughout the river system.

The lock was built as part of Hamburg's water management system to enable boat traffic and control water levels along the Alster. It has remained a key part of regional navigation and river management infrastructure ever since.

The lock's name comes from Poppenbüttel, and its chamber was built 143 metres long so that at least five vessels could be sluiced together, saving water for the Alster. A coat-of-arms stone of 1859 set in the retaining wall about 15 metres upstream of the Bäckerbrücke marks Hamburg's authority over the river.

The lock is accessible via the Alsterwanderweg trail, which is well-marked and easy to follow. The nearby Alstertal Shopping Center and public transportation make visiting straightforward and convenient.

The lock's chamber was 143 metres long, sized so that at least five wooden Alsterböcke (15–24 m long, 3.5–5 m wide) could be sluiced together to save water. A coat-of-arms stone of 1859 set in the historic retaining wall about 15 m upstream of the Bäckerbrücke still marks Hamburg's sovereignty over the Alster.