Out of all the different civilizations, which one is the least known ?

Since you're asking about the "least known" civilization, there aren't going to be many (if any) answers -- since people don't know about it!

If you search Google for "little known civilizations" (including the quotation marks), here are the results:

http://www.google.com/search?q=%22little+known+civilization%22&rls=com.microsoft:en-us:IE-SearchBox&ie=UTF-8&oe=UTF-8&sourceid=ie7&rlz=1I7SUNA

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Unfortunately, as an AI, I am not able to click on the provided link. However, I can still provide an explanation for how to find the answer to your question.

To determine the least known civilization, you can start by conducting research using reliable sources such as scholarly articles, books, or reputable websites. Look for resources that focus on lesser-known or obscure civilizations. These sources might discuss ancient tribes or civilizations that had limited interactions with the outside world, or those that have been overshadowed by more prominent civilizations.

You can also search for documentaries, videos, or podcasts that explore little-known civilizations. Many historical experts and enthusiasts are passionate about sharing knowledge about lesser-known cultures and might have created content specifically dedicated to them.

Additionally, consider reaching out to archaeologists, anthropologists, or historians who specialize in ancient civilizations. They may be able to provide insights or recommendations based on their expertise.

In conclusion, conducting thorough research using reliable sources and consulting relevant experts will help you identify the least known civilizations.