Hain
Hain is the Prime World in the Hainish Cycle and is also known as Davenant and Hain-Davenant. It is the oldest culture in both the League of Worlds and later the Ekumen and is about 140 Light Years from Terra/Earth. Observers like Genly Ai in The Left Hand of Darkness are trained on Hain.
Hain is supposedly the ultimate source of most intelligent life in the planets of the Ekumen. Its people cannot conceive children or father them without a conscious decision to do so. It once had a high-technology culture, and also seeded humans or humanoids on various planets, including Earth and other worlds now in the Ekumen. The history of the people of Hain goes back three million years.
From the older high-tech culture there was a crash and a re-building on a wiser basis. Evidence of the former high-tech life is all around, along with proof of the current indifference to it:
Stse is an almost-island, separated from the mainland of the great south continent by marshes and tidal bogs, where millions of wading birds gather to mate and nest. Ruins of an enormous bridge are visible on the landward side, and another half-sunk fragment of ruin is the basis of the town's boat pier and breakwater. Vast works of other ages encumber all Hain, and are no more and no less venerable or interesting to the Hainish than the rest of the landscape.
Three of the short stories in A Fisherman of the Inland Sea include details of life on Hain. More is seen in the first half of A Man of the People in Four Ways to Forgiveness. Havzhiva is a man who grows up on Hain, though he ends up working for the Hainish embassy on Yeowe. We see the ruins of past technology and learn of the highly localised social order that exists on some parts of the planet.
Read more about this topic: Planets Of The Hainish Cycle