A spectacular video shows what a Pictish fort might have looked like 1600 years ago.

The clip is based on research carried out by the University of Aberdeen at an eroded sea stack near Dunnottar Castle, just south of Stonehaven, Aberdeenshire.

Archaeologists say the stack, named Dunnicaer, was the site of a major Pictish fortification in the third or fourth centuries.

Although the site now measures just 20 x 12 metres, it was formerly much bigger and connected to the mainland.

With the help of experienced mountaineers, the team discovered partial remains of houses on the cliff edge, which shows that much of the settlement had fallen into the sea.

Turf and timber structures were found stacked on top of each other, suggesting space was always at a premium on the site.

Roman pottery and glass were also discovered at the site, suggesting the inhabitants had connections to the Roman world.

To mark the team's discoveries, a video was funded by Historic Environment Scotland showing how the fort might have looked in its heyday.

Professor Gordon Noble, of the university's archaeology department, said it appears that the site was abandoned in the late fourth or early fifth century. The settlement may have shifted to Dunnottar, which was an elite centre of Pictish society by the seventh century.

"We always knew that Dunnicaer was a site of major significance but carrying out an archaeological survey was hampered by the inaccessibility of the site," the professor said.

"Thanks to the help of mountaineering experts, we were able to carry out some extreme archaeology.

"It is plausible that, although already in an eroded state, the outcrop would have been significantly bigger in the time of the Picts, making it a suitable site for a settlement.

"This video helps to fully visualise how the fort may have looked in the fourth century which we think helps to further bring to life the lives of the Picts, who are so poorly understood because of the lack of historical records.

"We're so glad we have been able to do the dig on Dunnicaer at this time. Coastal erosion is a huge threat to archaeological sites of this kind and the remaining stack will continue to erode."

The site originally came to the attention of researchers in 1832 after a group of youths from Stonehaven scaled the sea stack and found a number of decorated and carved Pictish symbol stones.

The radiocarbon dates for the settlement suggest that these stones may be amongst the earliest found in Scotland.