We could have drawn a blank about the rich and unparalleled civilization of Indus Valley people, but for the efforts of John Marshall, the well-known Archaeologist, who brought it to light in 1921. The excavations made in Mohenjo-Daro and Harappa - (both are in Pakistan) revealed the prestigious civilization of our ancient Indians.
This civilization dates back between 3000 to 1500 BC. The other excavated sites are Lothal, Rupar, Rangpur, Chanhudaro, Amri, Lohumjo-duro, Ali Murad, Jhukar etc. From the available remains, we can conclude that the Indus Valley people had excelled their contemporaries in Mesopotamia, Egypt and Sumaria in architecture.
They had constructed wide and straight roads. The drainage system ran along the sides of the roads. In the center of the village, a swimming pool 'Great Bath' had been constructed. They used red burnt bricks. They had commercial contacts with the foreigners in Egypt and Sumaria.
The Indus Valley people used gold, silver, copper, tin etc. But they did not know the use of iron. It is believed that their civilization might have been destroyed by the Aryans. The Indus Valley people probably might have spoken Dravidian language. The 'Pictographic' script of Indus Valley is not yet deciphered.