What bridge did Leonardo da Vinci design to swing or rotate aside, allowing ships to pass?

Leonardo da Vinci designed a revolving bridge that could swing aside to let ships pass.

The bridge belonged to his studies of military and civil engineering. A movable span could provide a crossing for people and troops while also opening a waterway for boats. Leonardo’s drawings show how counterweights and supporting structures might make the bridge easier to move and restore to position.

A revolving bridge is different from a conventional drawbridge, which normally lifts upward, and from a pontoon bridge, which floats on linked platforms. Leonardo’s design emphasized horizontal movement around a pivot. It was a proposal rather than a surviving bridge known to have been built under his direction.

His bridge studies reveal how closely he connected transportation, hydraulic engineering, and military planning. Movable bridges remained useful wherever roads crossed navigable rivers or defensive waterways.