The island of Papay, lying about 20 miles to the north of Kirkwall, is home to 60 archaeological sites.

Among these are the incredibly well-preserved remains of the earliest known dwellings in Orkney — and the oldest standing buildings in northern Europe.

These structures, two oblong, stone-built houses, date from approximately 3,600 BC and were continuously occupied by a series of Neolithic farmers for at least five centuries.

The buildings, on the island's west coast, were uncovered in the 1930s when severe sea erosion revealed deposits of midden material, as well as evidence of well-built, stone walls.

This chance discovery led to the excavation of the site. After more than two metres of sand were removed, the underlying building was revealed. This "building" actually turned out to be two stone-built structures, placed side-by-side and linked by a passage through the joined walls.

At the time of the excavation, a few artefacts were uncovered but nothing that allowed the experts of the time to date the site correctly. As a result they declared the Knap o' Howar to be an Iron Age site.

More recent excavations, however, have shown that the Knap o' Howar was in use between about 3,600 BC and 3,100 BC. They were probably part of a small farm, the home of a Neolithic Orcadian family that remained in use for hundreds of years.

The two connected structures formed a dwelling house and a multipurpose workshop/barn. With walls still standing to a height of 1.6 metres (5 feet), the dwellinghouse is the largest and best preserved of the two buildings. It is reasonably spacious and divided into two living areas by large upright stone slabs.

How the dwelling at the Knap o' Howar would have looked during the period of its use.

The outer chamber has a low stone bench running along the wall, while excavations in the other chamber indicated that it was probably a kitchen of sorts, with a central hearth and footings for wooden benches.

The large stone quern, used for grinding barley, together with a smaller variant still lie where they were found all those years ago.

The "workshop" has a similar entrance to the main house but was separated inside into three distinct areas by a series of large stone slabs.

A few curious facts surround this section of the structure - such as the fact that the door joining the two sections was set in the workshop side. From this, it would appear that the workshop went out of use during the life of the main house, for both its entrances were found to have been blocked with stones.

The excavations also revealed that the current houses were not the first on the site, but may actually have been built upon the midden remains of an earlier, even older, structure.