Humanity's long attachment to Yorkshire has notched up another piece of early evidence with the discovery of the first 7th-century house to be recorded in the Dales national park.

Volunteer archaeologists dug down into an outcrop of stones on the flanks of Ingleborough fell, one of the Three Peaks famous for walks and marathon runs, where settlements were thought to exist but none had been excavated owing to shortages of time, expertise and funds.

The team revealed two chamber rooms with charcoal remains and pieces of chert, a hard flint knapped in ancient times to make tools.

Carbon-dating of the charcoal has placed the use of the building at between AD660 and AD780, when Anglo-Saxon kingdoms were consolidating in northern England.

The dig adds to a growing list of discoveries, from a Roman amphitheatre at Aldborough to exquisitely carved golden rings near Leeds, which are changing the history of the north of England.

In each case, archaeologists have suggested that the relative poverty of previous finds in the region, compared with southern counties, has had more to do with where the profession previously looked rather than what may be there.

Robert White, senior historic environment officer for the Yorkshire Dales national park, said: "We have a wealth of archaeological sites but very few have been excavated and even fewer since scientific dating techniques became widely available.

"This is the first building in the national park that is firmly dated to the 7th century and is one of only a handful in the north – that shows just how much unrecorded archaeology there still is.

"Although very little written information survives for the period between the ending of Roman occupation in about AD410 and the Norman conquest, archaeological evidence in many other parts of the country has shown it to be a culturally rich and politically dynamic period."

The dig was carried out by amateur enthusiasts from Ingleborough Archaeology Group on the fell's flank near Selside in upper Ribblesdale.

Their 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.

"The two were sent for radiocarbon dating and returned identical dates, which makes this building the only firmly-dated, post-Roman archaeological site in Ribblesdale – which is of more than local significance."

The chert is thought to have come from early neolithic remains on the summit of Ingleborough, which served as a fortified camp 6,000 years ago.

Johnson said: "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."

Roger Bingham, a champion of cultural heritage at the national park, said amateur enthusiasts were playing a vital role in revealing the hidden history of the north.

"They are only amateur in that they are unpaid," he said. "In every other way – in methods of working and, above all, in recording – their expertise is thoroughly professional and we are pleased to have been able to provide financial support towards some of their expenses, such as carbon dating, through our research budget."

The site has been backfilled to protect the finds, while further digs are planned at other suspected settlement sites in the Three Peaks area, which also includes the fells Pen-y-ghent and Whernside.

England's oldest-known dwelling was discovered in August last year – in Yorkshire. The circular wooden and thatched home, found beside a long dried-up lake near Scarborough, dated back 10,500 years.