Bridges have evolved from tree trunks across rivers to massive steel structures spanning across the ocean linking one land to another. With the advancement of technology, bridges were built based on the sustainability of the materials used, making them more and more practical as the ages progressed.
As illustrated above, tree trunks were used as bridges across rivers in the ancient times. They then evolved into rope bridges, made primarily out of vines and grasses, suspended across valleys.
Then came the clapper bridges made of large slabs of stone. This gave way to the stone arch bridges during the Roman Empire and the Middle Ages, through the Renaissance period onwards.
After the stone bridge period, came the steel suspension bridges. The Brooklyn Bridge in New York was the first ever steel suspension bridge, supported by steel wires. As technology advanced further,
bridges were built using reinforced concrete for longer sustenance.
From 1931 on, bridges were more commonly built using steel and reinforced concrete instead of stone and so on. Many massive steel and reinforced concrete bridges around the world that were built in the earlier years are still standing majestically today. One of them is the world renown Golden Gate Bridge of San Francisco.
