Paleolithic age starts from 3 million and 200 thousand years until 18 thousand years ago; the time that Human discovered fire. Hunting, gathering plants and settlement in natural shelters are the main characteristics of this age. About 200 thousand years ago, Neanderthal appeared on the earth and sharpening tools were invented, simple shelters were formed and human being started using animal furs to keep themselves warm. The first traces of burial traditions belong to Paleolithic age as well, the age that intelligent human made impressive development in tools making. Also, the first traces of art on walls of caves and rocks were appeared in this age. At the end of this era, human beings were able to sew clothes for themselves. The oldest signs of humankind have been unearthed in Kashafrud River in Khorasan which date back to 800 thousand years ago. Mount Khajeh in Sistan, Bisotun Caves, Do-Ashkaft Cave and Niasar are other places having the remnants of Paleolithic age.
Mesolithic age is the period between 18 thousand years until 10 thousand years ago when human being deliberately started to gather and preserve food, cultivate plant seeds, and domesticate animals. The traces of humankind existence in this era can be seen in the caves of Kamarband, Hotu and Gomishan, Ganj Dareh in Hersin and the banks of Zayanderud River.
The period from 10 thousand years to 6 thousand years ago is called the Neolithic age. The early human successfully began farming and domesticating animals in this era. The dishes made of clay and straw came into use to preserve and have their foods. The houses were also built with mud and in a circular shape and evolved gradually. The most important change of this era was the rise of faith and creation of gods and goddesses that led to specific burial traditions and formation of cemeteries. The art of this era was abstract and stylized. The most well-known sites of Neolithic age in Iran include Tall-i Bakun, Tall-I Jarri, Susa, Chogha Bonut, Chogamish and Sarab Teppe.
Following the formation of agriculture, people emigrated from mountainous areas to the plains, which led to permanent settlement and creation of villages which is from 6,000 till 3,500 year B. C. The evidences of the primary villages of Iran can be found in Jiroft, Sialk, Ganj Dareh and Susa.
With the discovery of metals and copper in particular, the world began a new phase. Tools consisted of copper and stone were built in this age and that is the reason of calling this age Chalcolithic which was roughly from 2500 to 3000 BC. The presence of metal, however, did not mean the disappearance of pottery and clay related works. Clay became more important and use of Potter’s wheel became common in many of the regions. In this age, potteries were adorned with pictures of horned animals, birds, reptiles as well as human in different patterns and styles. The various Chalcolithic sites in Iran include Tall-i Bakun, Godin Tepe, Teppe Gian, Tepe Sialk, Tepe Hissar, Chogamish, Susa and etc.
The beginning of urbanization in Iran dates back to 4000 years B.C. The first cities of Iran are Susa, Shahr-e Sukhteh in Zabol (Burnt City), Jiroft, Tepe Hissar, and Sialk. Following the formation of urbanization, different social classes and jobs were slowly created. In this era, the architecture of the places included houses that had roof gutters for rainwater and special places for flowing of water in the passageways.
At the beginning of the fourth millennium B.C., human could discover an alloy called Bronze. This era starts from the beginning of forth millennium till the middle of second millennium. The oldest bronze objects of Iran were found in Lorestan province. Grey pottery was produced excessively in Iranian plateau. Before the Bronze Age, dead bodies were buried in the floors of houses in an embryonic style, but burial tradition in cemeteries started in this age.
From 1500 to 1000 year B.C, human achieved the technique of making metal tools. The most important accomplishment of Iron Age was the ability to make more durable war equipment. Another important invention of this age was glass objects. In this era, the ethnics like the Medes and Persis emerged, they were the great ethnics of the region and Iran entered its historical era.