For example, the first bridges made by humans were probably just wooden logs placed across a stream and later timber trackways.In addition to living in caves and rock shelters, the first buildings were simple shelters, tents like the Inuit's tupiq, and huts sometimes built as pit-houses meant to suit the basic needs of protection from the elements and sometimes as fortifications for safety such as the crannog.Built self-sufficiently by their inhabitants rather than by specialist builders, using locally available materials and traditional designs and methods which together are called vernacular architecture.The very simplest shelters, tents, leave no traces.Bronze was cast into desired shapes and if damaged could be recast. Other uses of copper and bronze were to "harden" the cutting edge of tools such as the Egyptians using copper and bronze points for working soft stone including quarrying blocks and making rock-cut architecture.During the Bronze Age the corbelled arch came into use such as for beehive tombs.The smaller dwellings only survive in traces of foundations, but the later civilisations built very sizeable structures in the forms of palaces, temples and ziggurats and took particular care to build them out of materials that last, which has ensured that very considerable parts have remained intact.
The Iron Age is a cultural period from roughly 1200 BC to 50 BC with the widespread use of iron for tools and weapons.
Copper came into use before 5,000 BC and bronze around 3,100 BC, although the times vary by region.
Copper and bronze were used for the same types of tools as stone such as axes and chisels, but the new, less brittle, more durable material cut better.
The tools available were made from natural materials including bone, antler, hide, stone, wood, grasses, animal fibers, and the use of water.
These tools were used by people to cut such as with the hand axe, chopper, adze, and celt.The wheel came into use but was not common until much later.