Loch Eriboll cuts 16 kilometres into the north coast of Sutherland, a deep, sheltered fjord that has been used as a safe anchorage for centuries. The seas off Cape Wrath and through the Pentland Firth are among the most violent in Europe - tidal races collide, gales pile in from the Atlantic, and a ship caught out can be in trouble within minutes. Eriboll offers escape. The walls drop steeply enough that warships can lie close to shore in deep water, and the loch is wide enough to swing at anchor. The Royal Navy used it heavily through both world wars. In 1944 the Fleet Air Arm even practised aerial bombing here, treating Eilean Choraidh - the largest island in the loch - as a stand-in for the German battleship Tirpitz before the successful Operation Tungsten raid in Norway that April.

On 8 May 1945, Germany surrendered. Karl Donitz signalled his remaining U-boat captains to surface, fly a black flag, and steam to the nearest Allied port. Many came here. The 33 surviving German U-boats that surrendered at Loch Eriboll arrived one by one through May - long, low silhouettes nosing into the calm water under the guns of the Royal Navy. Their crews were taken off and processed. The boats themselves were inspected, then mostly transferred to Lisahally in Northern Ireland and eventually sunk in Operation Deadlight, the deliberate scuttling of the Kriegsmarine submarine fleet. Eriboll did not feature in the major battles of the Atlantic. It featured in their ending. The loch that had sheltered Royal Navy convoys through six years of war also held the moment those convoys no longer needed to be there.

Long before the warships, Loch Eriboll had a quieter history. Bronze Age people built a souterrain and a well-preserved wheelhouse on the hillside above the west shore - stone-walled, semi-underground homes that survived the millennia mostly because nobody disturbed them. Around 1870, four large lime kilns were built on Ard Neakie, a small promontory on the eastern shore, to burn local limestone into agricultural lime. Before the coast road went in around 1890, the only way to cross the loch was the Heilam ferry, running from Portnancon on the west side to Ard Neakie on the east. Both were also fishing stations. Today the crofting townships of Eriboll, Laid, Heilam and Portnancon remain scattered along the shore. The MoD still leases a slice of the loch as a minor training area for amphibious exercises, but for most of the year Eriboll is what it has always been - a long, quiet sea loch in a region that holds the lowest population density in the United Kingdom.