The Indus Valley civilization was one of the largest, most advanced civilizations in the ancient world. But we barely know anything about them, in large part because we haven’t been able to decipher the cryptic symbols they left behind.For more, go to http://vox.com/unexplainableIt’s a great place to view show transcripts and read more about the topics on our show.Also, email us! unexplainable@vox.comWe read every email.Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcastsLearn more about your ad choices. Visit podcastchoices.com/adchoices