Tssaksa

The land of snakes and snake people, and home of the yuan-ti, Tssaksa is perhaps the most mysterious country in the known world. Few of the "civilized" races have entered the country and returned home alive, though those that do tell tales of great cities built by slaves stolen from other lands, whose grim fate is to eventually be eaten once they are no longer useful...

In addition to the many raids they commit to their neighbours in Edanka, yuan-ti spies often sow chaos outside their mysterious homeland, for reasons known only to themselves.

History
It is known that even during the First Age, the elves refused to try and colonize Tssaksa, for fear of the mysterious snakemen that inhabited the sub-continent.

Even the Edan Empire was unable to establish a presence in the dense jungles of Tssaksa, and decided instead to blockade the nation using their navy. This did little to dissuade the yuan-ti, and the area was only added to the Edan Empire on paper during their great conquest.