Archaeologists at the Petrified Forest National Park in Arizona have discovered an ancient village they say is unique for its size.

Park officials say the 50 to 70 pit houses are organised in rings on about 26 hectares.

Archaeologists say the dwellings were built more than 1000 years ago in the Basketmaker period. They say that’s when groups of people started settling together in villages.

Made of stone slabs the houses were found in sand dunes. Traces of stone tools and early ceramics were also found nearby.

The discoveries are part of three-year, grant-funded project to survey more than 18,000 hectares of land added to the Arizona park since 2004.

The village was found on the eastern portion of the site and follows a similar, smaller-scale discovery last year.