A "Rhino" seal from Indus Valley Civilization also know as Indus-Saraswati Civilization was at its peak period at around 5000 years ago and it flourished around river Indus and Saraswati and spanned from Afganistan to Gujarat, India. The apparent migration of population from Indus Valley because of reduction in water of Indus and mysterious disappearance of River Saraswati led to modern Indian Civilization. Saraswati River being mention in Rig Veda. The oldest site is found at Mehrgarh which dates back to 7500 years old. Most of these cities were having a huge infrastructure and used baked bricks for construction which weren't used in other parts of the world.