The age of first urbanisation is the period related to Harappan culture or the Indus Valley civilisation. It was the era of bronze age where iron was not known to people but still urban centres were developed. Town planning was a distinctive feature of that era. Art and craft was well-developed during the Harappan culture. This period was completely different from the pre-historic period settlement and that is why, this is often referred as the age of first urbanisation. The Indus Valley civilisation marked a shift of a tribal society to a civilised society.