One of the earliest civilizations was in the Indus Valley in today's Pakistan. Also known as the Harappan civilization, it originated some 4,500 years ago and was a contemporary of the civilizations in Mesopotamia and Egypt. In fact, artifacts tell us that the Harappans traded with Mesopotamia. They were quite advanced, too, with their buildings containing such amenities as indoor plumbing. The problem for moderns is that, if you obtained an Indus Valley plumbing manual to unclog a toilet, you would have no way to understand it.
The Indus Valley civilization's writing system contained over 400 different symbols. These are found on a variety of artifacts, including tags used on trade goods. Nobody knows what they mean, though that doesn't stop people from trying to decipher them. Experts have counted the occurrences of the symbols and have concluded that, because so few symbols appear numerous times on solid artifacts, most writing must have occurred on materials that could not withstand the test of time, such as palm leaves.
The chances of deciphering this writing system are slim. One major obstacle is that there is no bilingual example of an Indus Valley text next to a known writing system, such as the Rosetta Stone that was used to decipher Egyptian hieroglyphics. The other problem is that experts have no clue what original language the signs represent. This problem will continue to make the ancient Indus Valley a mystery.
[Image by Geni via Wikimedia Commons | Cropped and scaled | CC BY-SA 4.0]
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