Arch bridge
An arch bridge is a bridge with abutment
An abutment is, generally, the point where two structures or objects meet. This word comes from the verb abut, which means adjoin or having common boundary. An abutment is an engineering term that describes a structure located at the ends of a bridge, where the bridge slab adjoins the approaching...

s at each end shaped as a curved arch
An arch is a structure that spans a space and supports a load. Arches appeared as early as the 2nd millennium BC in Mesopotamian brick architecture and their systematic use started with the Ancient Romans who were the first to apply the technique to a wide range of structures.-Technical aspects:The...

. Arch bridges work by transferring the weight of the bridge and its loads
Structural load
Structural loads or actions are forces, deformations or accelerations applied to a structure or its components.Loads cause stresses, deformations and displacements in structures. Assessment of their effects is carried out by the methods of structural analysis...

 partially into a horizontal thrust restrained by the abutments at either side. A viaduct
A viaduct is a bridge composed of several small spans. The term viaduct is derived from the Latin via for road and ducere to lead something. However, the Ancient Romans did not use that term per se; it is a modern derivation from an analogy with aqueduct. Like the Roman aqueducts, many early...

 (a long bridge) may be made from a series of arches, although other more economical structures are typically used today.
Possibly the oldest existing arch bridge is the Mycenaean
Mycenaean Greece
Mycenaean Greece was a cultural period of Bronze Age Greece taking its name from the archaeological site of Mycenae in northeastern Argolis, in the Peloponnese of southern Greece. Athens, Pylos, Thebes, and Tiryns are also important Mycenaean sites...

 Arkadiko bridge
Arkadiko Bridge
The Arkadiko Bridge or Kazarma Bridge is a Mycenaean bridge near the modern road from Tiryns to Epidauros on the Peloponnese, Greece. Dating to the Greek Bronze Age, it is one of the oldest arch bridges still in existence and use....

 in Greece from about 1300 BC.