The Bronze Age settlers left evidence of several small oval houses with thick stone walls and various artefacts including a decorated bone object.

The Viking Age ruins make up the largest such site visible anywhere in Britain and include a longhouse; excavations provided numerous tools and a detailed insight into life in Shetland at this time.

The most visible structures on the site are the walls of the Scottish period fortified manor house, which inspired the name "Jarlshof" that first appears in an 1821 novel by Walter Scott.

[3] In 2012 "Zenith of Iron Age Shetland" including Mousa, Old Scatness and Jarlshof was added to the UK's tentative list of proposed World Heritage Sites.

The site overlooks an arm of the sea called the West Voe of Sumburgh and the nearby freshwater springs and building materials available on the beach will have added to the location's attraction as a settlement.

The south Mainland also provides a favourable location for arable cultivation in a Shetland context and there is a high density of prehistoric settlement in the surrounding area.

Other than the Old House of Sumburgh (see below) the site remained largely hidden until a storm in the late 19th century washed away part of the shore, and revealed evidence of these ancient buildings.

[19] There is also evidence of a cattle stall with a waste channel leading to a tank in a courtyard and a whale vertebra set into a wall that may have been used as a tethering post.

Broken moulds from the smithy indicate that axes, knives, swords and pins were produced there and a bronze dagger was found at the site.

The tower was probably originally 13 metres (40 feet) or more high and as with many broch sites the position would have commanded fine views of the surrounding seas.

[28][31] Three successive periods of construction were undertaken, and the best preserved retains a significant proportion of the stone part of its roof and displays a series of corbelled bays.

[37] In AD 43 and 77 the Roman authors Pomponius Mela and Pliny the Elder referred to the seven islands they call Haemodae and Acmodae respectively, both of which are assumed to be Shetland.

Another early written reference to the Shetland islands may have been when Tacitus reported that the Roman fleet had seen "Thule" on a voyage that included the Orkney archipelago in AD 98.

[40] Sheep, cattle, pigs and ponies were kept, Atlantic cod, saithe and ling were eaten, and whale and seal bones have also been found along with the remains of a single dog.

[8][42][43] The largest house from this period is a 20-by-5-metre (66-by-16-foot) rectangular chamber with opposing doors, timber benches along the long sides, and a hearth in the centre.

The mystery was solved when a byre door was excavated at Easting on Unst which had a narrow base similar to Jarlshof's but which widened out to become cow-shaped.

[39] The drawings were found in the Viking levels but are Pictish in style and may either pre-date the arrival of the Norse or indicate a continuity of art and culture from one period to the next.

[8][49] Similarly, although the rectangular shape of the Norse-era buildings are quite unlike the earlier rounded Pictish style, the basement courses of the two periods are constructed in the same way.

Originally a medieval stone farmhouse, it was converted into a fortified house during the 16th century, by Robert Stewart, 1st Earl of Orkney after Scotland annexed Shetland.