Cracauer Wasserfall, Free overfall weir in Magdeburg, Germany.

The Cracauer Wasserfall is a concrete weir structure that spans approximately 130 meters across the Old Elbe River and manages water flow through the channel. An opening in the middle allows water to pass through while excess water spills over the top when levels rise.

A first overfall weir, the "Roste" or "Presterscher Sperrdamm", was built in 1684/86 at the Rotehornspitze to divert water into the Strom-Elbe. The Cracauer Weir itself was built in 1819/20 at the site of today's structure, with an overflow length of 180 m; it was rebuilt in 1867/68 after the crest subsided. French troops blew a 50 m gap in the earlier dam in November 1806. The present form dates from 1968/69, when the crest was raised to compensate for riverbed erosion.

The name comes from the nearby area of Cracau and serves as a landmark for visitors exploring this part of the city. The spot draws people interested in water sports and those simply watching the river from the banks.

The weir can be accessed from walkways along the Old Elbe River and is viewable from several sides, particularly from the adjacent bridge. Visitors should watch for slippery surfaces near the water, especially when water flow is faster.

Until 1968 a Chinese mitten crab trap stood at the weir. Before the nearby bridge was built, and again during its renovation, people crossed the Old Elbe over the weir at low water; in 2017 the water police enforced a ban on this.