Trees grow on a crannog, an artificial island, in a loch

Experts will investigate the area's ancient cairns, brochs, crannogs, castles and shipwrecks.

With the help of local divers, they also hope to solve the mystery sinking of a World War I German warship.

There will be nothing of this scale anywhere else in the UK running at the same time this year.

The Early Architecture Research Programme (EARP) will begin its investigations later this month.

We're keen to finally solve the mystery of what happened to the V81 Archaeologist Simon Davidson

The projects will include modern reconstructions of Neolithic chambered cairns and Iron Age brochs.

Brochs were stone towers built to impress and were probably houses for tribal chiefs or important farmers.

Crannogs were artificial islands created in lochs as a place to live and were linked to the shore by a stone causeway or timber gangway.

John Barber of AOC Archaeology Group will lead the research and an excavation of an Iron Age broch at Keiss.

He said: "The excavations this year are only the start to enable more extensive excavations next year and for four years thereafter.

"The Keiss Broch is a magnificent site with a central broch and a surrounding village."

The dig will coincide with excavation of another broch in Caithness by Andy Heald of the National Museums of Scotland.

A team from the University of Glasgow, led by Kenny Brophy, is headed for Battle Moss to investigate a Bronze Age cairn and associated stone rows.

York-based Field Archaeology Specialists and the Caithness Archaeological Trust will also continue earlier work done at Sinclair Girnigoe Castle.

It is one of the many castles throughout Scotland and the Orkney and Shetland islands held by the Sinclair Earls of Caithness.

Archaeologists reconstructing a stone cairn

Two new underwater archaeology projects will also begin this year.

Archaeologists from AOC Archaeology Group and the University of Nottingham will undertake surveys of the now submerged crannogs.

Graeme Cavers, who will be leading the team, said: "We intend to take samples from these crannogs for radiocarbon dating.

"The survey of the crannogs in the Loch of Yarrows, Loch Calder, Loch Watten and Loch Scarmclate will add a further dimension to our understanding of prehistoric settlement in Caithness."

Another team of underwater archaeologists from Nottingham University's Underwater Archaeology Research Centre will attempt to investigate the many shipwrecks off Caithness.

German destroyer

Archaeologist Simon Davidson, who is co-ordinating the project, has linked his team with Caithness Dive Club.

Mr Davidson said: "The region is steeped in maritime history - evidence for which is still lying there on the seabed."

"We're keen to finally solve the mystery of what happened to the V81, a World War I German destroyer which sank in 1921 off Sinclair's Bay whilst being towed south from Scapa Flow.

"The wreck is badly broken up, and it has been hard to conclusively prove its identity from desk-based records alone, but Caithness Diving Club assure me it is the V81.

"We're going to do some diagnostic comparison with her sister ship, the V83 which is interred at Scapa, and then we'll know for sure."

All of the projects are taking place with the full support of the Caithness Archaeological Trust.