Zdymadlo Brandýs nad Labem, River lock in Brandýs nad Labem-Stará Boleslav, Czech Republic

Zdymadlo is a lock system on the Elbe River that allows boats to pass through sections where the water level changes significantly. The facility uses gates and chambers to raise or lower vessels so they can continue their journey along the river.

The weir and lock were built in the third stage of the Elbe–Vltava waterway project, with construction starting in 1930 and finishing in March 1936; the functionalist design was by architect Kamil Roškot. They replaced an older fixed weir of the Old Prague type at the same spot. The lock chamber was fully rebuilt in 1974–1976 by the Polish firm Navga SPELWAR, which also built the control house.

The weir's footbridge carried the public across the Elbe until March 2013. Below the Podzámecký mlýn mill, a 330 m artificial slalom course was built in 1979, with a 50 m warm-up pool, a surf wave and a 250 m slalom run. The mill race itself passes under a stone bridge from 1603.

The lock is accessible from walking paths along both banks where you can watch operations easily throughout the day. Morning visits tend to offer more boat activity to observe.

The weir's footbridge served as a public crossing of the Elbe until March 2013. The weir stands 3.65 m high, with three 23 m spans separated by pillars 18 m long and 3.6 m wide; each steel gate structure weighs 149 t.