Final answer:
The best known Indus Valley archaeological sites are Harappa and Mohenjo-Daro, which were part of a highly urbanized civilization known for town planning, residential and industrial districts, and a complex writing system.
Step-by-step explanation:
The Indus Valley Civilization was a highly urbanized society known for its advanced urban planning, which included archaeological sites such as Harappa and Mohenjo-Daro. These cities were likely organized as independent city-states or had large cities functioning as regional capitals. Harappa, being the first discovered site by modern archaeologists, has become synonymous with the Indus Valley civilization itself. Excavations at these sites revealed sophisticated grid street systems, efficient drainage, and buildings equipped with amenities such as wells for running water. The cities showcased an industrial district and were notable for their residential quarters, workshops, and evidence of a complex writing system known as the Indus script. This civilization was spread across what is now Pakistan and India, with evidence of farming, artisanal crafts, and a rich spiritual life.
Harappa and Mohenjo-Daro stood out among the urban centers in the Indus Valley due to their size, with populations of about thirty thousand people each. They demonstrate the technologically advanced nature of the civilization that emerged around 2000 BCE. The lack of elaborate monuments or obvious signs of rulership suggests a culture defined more by communal utility and shared culture rather than dominated by warrior-kings or centralized despotic authority.