ARCHAEOLOGISTS are hoping they may soon be able to shed light on the past history of mysterious Iron Age ruins in the Highlands.

Geophysical scans of the land around two ancient roundhouses known as brochs have uncovered tantalising evidence they were part of wider settlements.

Brochs date to the first century AD and are unique to Scotland. The stone towers, which can stand several storeys high, have baffled historians for centuries and their exact purpose remains a mystery.

Most have been reduced to mounds of rubble or simple features on the landscape, but some are surprisingly intact given their age.

Scientists and enthusiasts working Bruan Broch, the first site being examined, found evidence of further structures to the southwest and southeast.

They believe this may be evidence of a settlement known as a ‘wag’, which are sometimes associated with former broch sites.

Brochs were once believed to be forts, but that theory has fallen out of favour because they are often built on ground which would not have been defendable.

It has also been suggested that they were the "stately homes" of Iron Age Chiefs, but this has been debunked given the sheer number - more than 500 - which dot the landscape.

Geophysics data from the second site at Thing's Va Broch near Thurso indicated more recent buildings nearby which may be linked to the structure's Norse heritage.

The broch takes its peculiar name from the Viking word for parliament, as it was reused by settlers from Scandinavia when they arrived in the region during the Dark Ages.

Scans also showed an "anomaly" to the northeast of the broch which could represent a burnt mound. A cairn to the south is also being suggested as the site of a substantial roundhouse from the Late Iron Age.

The discoveries were made during work undertaken by the Orkney Research Centre for Archaeology and the University of the Highlands and Islands Archaeology Institute as part of the Caithness Broch Project.

Further archaeological digs will now take place at the two sites in Caithness later this month.

Dan Lee, Lifelong Learning and Outreach Archaeologist at the Archaeology Institute, said: “We are looking forward to finding out more about these two important broch sites.

"The trial trenching, together with geophysics data gathered last month, should help us understand more fully the story of these two important sites.”