Unknown events: Many bridges were made in prehistoric times. Most of these were very simple, like stacked stones that support a stone slab or a fallen tree acting as a beam.
The Romans built many bridges in their time. These bridges were usually bigger than they had to be, but this was done by the Romans in order to ensure that the structures were safe and would not prove dangerous. The one shown above is thought to be built in 19 B.C.
Most bridges built back then were built of an early form of concrete or stones.
Early cantilever bridges were built in China and Tibet out of timber. These were built at least 1900 years ago.