Archeologists think they have found the ruins of the Great Hall of King Harald I Fairhair (Haraldr Hárfagri) at Avaldsnes in west Norway.
It was the site of the halls of local chieftans and then the Kings of Norway for almost 3000 years until the settlement was burned by the Hansa Merchant League in 1398.
Thank you for pointing out that the link is in Icelandic.
Oops, my bad.
Here is the original Aftenposten link (in Norwegian, of course...)
http://www.aftenposten.no/nyheter/iriks/article1549809.ece
with a picture of the site adjacent to St Olavs church.
The Aftenposten might have an english version by tomorrow, they do have an english web site but it lags the original and not all the stories are translated.