Kris Taeleman | 
This bridge is the smallest drawbridge in the world and is barely wide enough to permit the mast of a sailboat to pass through.
The original bridge was built in 1620, and much of its structure remains, although the bridge was largely rebuilt in the mid 20th century. The original bridge was cranked open by hand, whereas the current bridge consists of two cantilevered half-spans, separated by a 32-inch (80 cm) gap bridged by a thick timber panel. The panel is removed whenever a yacht wishes to pass beneath the bridge, allowing the unsailed mast to pass through the gap.
- Wikipedia
You can check out an aerial image of the bridge at Google sightseeing.