A bridge in architectural reference is a structure built to span a physical obstacle such as a valley, body of water or road, without closing the way underneath. The main purpose of constructing a bridge is to build a passage over the obstacle, usually something that can be detrimental to cross otherwise. There are many different designs of a bridge, and each one serves a different purpose in different situations. The designs hence vary according to the function of the bridge, the nature of the terrain where the bridge is anchored and constructed, the material which has been used to make it and the funds and capital available to build it.
Most likely, as per resources, the earliest bridges were made of fallen trees and stepping stones. The revolution in the history of bridges initiated when the Neolithic people built boardwalk bridges across marshland. One of the oldest arc bridges, known to be in existence and use is the Arkadiko Bridge, in the Peloponnese, in the Southern Greece. This bridge has been standing since the 13th century BC. Sweet Track and Post track are examples of bridges built by the Neolithic people in England about 6,000 years ago.
In this sub category you can download free PNG images: Bridge Objects. In this category "Bridge" we have 13 free PNG images with transparent background.