Not many people would consider the slopes of a mountain the best place to build a home, but more than 1,300 years ago on the second highest peak in the Yorkshire Dales somebody did just that.

A team of amateur archaeologists has spent years studying the north-west flanks of Ingleborough.

And the work of the Ingleton-based Ingleborough Archaeology Group (IAG) has resulted in the discovery of the first seventh century building to be positively identified in the Yorkshire Dales – and one of the first in the north of England.

The small building was uncovered earlier this year at Upper Pasture, near Selside. It is believed to have been abandoned as long ago as the early Anglo Saxon period.

Excavation supervisor Dr David Johnson said: “We uncovered a small, rectangular, partly stone-built building with two rooms and in it we found 16 pieces of charcoal impressed into the compacted soil floor.

“Two of these were sent for radiocarbon dating and returned identical dates – between 660AD and 780AD, which puts the end of the site’s use firmly within the Anglo-Saxon period. That makes this building the only firmly-dated, post-Roman archaeological site in Ribblesdale – which is of more than local significance.”

A group spokesman said: “If the actual date was to be close to 660AD then this is an exceptionally early date for the Dales. If, on the other hand, the actual date was to be closer to 780AD then it is still highly significant.”

Dr Johnson added: “We also found small pieces of chert, a dark, rock-like flint that was knapped to make small tools. These are likely to date from the Early Neolithic period, possibly 6,000 years ago, and it was probably pure chance that the pieces found their way into the building – they may have been trapped in turfs used for sealing the walls or roof of the building.”

Many settlement sites have been identified between Ribblehead and Horton in Ribblesdale, including a well-known site near Ribblehead Quarry that was excavated in the 1970s.

Members of IAG have been surveying the archaeological features on the north-west flanks of Ingleborough since 2007 and 2011.

All of the recorded features were photographed and details have been entered on to a spreadsheet, which can be viewed at ingleborougharchaeologygroup. org.uk Robert White, the Yorkshire Dales National Park Authority’s senior historic environment officer, said: “This is an exciting discovery and one which is a credit to the group for the professional way they approached and conducted the excavation.”