
A sophisticated urban civilization flourished along the Indus River, spanning parts of modern-day Pakistan, northwestern India, and eastern Afghanistan between the 3rd and 2nd millennia BCE.
The Indus people left behind roughly 4,000 stone, bronze, and copper tablets covered in mysterious symbols and images of humans and animals, including bulls and a creature often called a unicorn. No scholar has been able to decipher the inscriptions on those tablets. Scholars say the writing system has no known parallels anywhere in the world.
Now the Indian government has launched an unexpected initiative. The government is offering a $1 million reward to anyone who can successfully decode these ancient, letter-like symbols.
“I am announcing a cash prize of one million U.S. dollars for individuals or organizations that can decipher the script,” said Muthuvel Karunanidhi Stalin, the chief minister of the Indian state of Tamil Nadu. He added that the mystery has gone unsolved for 100 years despite numerous attempts by archaeologists and other experts.

What You Need to Know About the Indus Civilization
This civilization, also known as the Harappan, was the largest by area but one of the least understood of the major ancient urban cultures. It flourished from 2600 to 1900 BCE and then suddenly disappeared from historical records, the Daily Mail reported.
Scholars know very little about this civilization. The Indus people left little archaeological evidence of warfare or other historical events. They communicated using one of the most unusual writing systems in the world.
The shortest inscriptions are five characters long, while the longest contain 34. Some experts even doubt that these symbols represent a language, suggesting they might instead be pictograms conveying religious or political messages.
Archaeologists first stumbled on the ruins of Indus settlements in the 1920s. So far, researchers have excavated about 1,000 of those settlements. They found the world’s earliest known toilets, sophisticated stone weights, drilled beads made from precious stones, and intricately carved stone seals.
“This was the largest urban culture of its time,” wrote scholar Andrew Robinson in a 2015 study published in the journal Nature.
Why did this civilization vanish? In recent years archaeologists have put forward two leading theories. The first suggests climate change—rising temperatures and a decline in monsoon rains—had catastrophic consequences for the population.
The second theory, backed by archaeological evidence, argues that deadly earthquakes played a major role in the disappearance of the Indus civilization.