BRIDGES Bridges can cross water. Some bridges over

water move to let boats through. Others are high enough that boats can pass beneath. Bridges also cross valleys, ravines, railroad tracks, roads, and other things that block the way.

Bridges can be made of many materials. Early bridges were made of wood or stone. Many wooden bridges were covered to protect them from snow and rain so they would last longer.

Golden Gate Bridge the golden gate Bridge is one of the world’s

most famous bridges. It spans the San Francisco Bay in California.

Wooden Bridge

Early bridges were usually made of wood or stone. This covered wooden bridge is on Virginia’s shenandoah riVer.

Ponte Vecchio

The Ponte Vecchio (Old Bridge) spans the Arno River in Florence, Italy. Built in 1345, the bridge was one of the few in Florence to survive the heavy bombing of World War II.

Ironbridge Ironbridge, located in Telford, England,

was the first bridge made entirely of cast iron. It was completed in 1779.

London’s Tower Bridge The Tower Bridge spans the Thames River in

London, England. It has a drawbridge that raises up to allow boats to pass through.

Suspension Bridge Suspension bridges hang from two large

main cables rather that resting on supports underneath. The Clifton Suspension Bridge, shown here, is located in Bristol, England.