Plans that could see six enormous underground oil tanks, built in Orkney during WWII, brought back into use are being investigated.
They are part of the largest structure in Orkney, dwarfing St Magnus Cathedral by quite some distance.
They took hundreds of men five years to complete – one of the biggest building projects in Orcadian history.
And, even more surprisingly, you can’t see them.
They are almost completely underground.
The World War Two oil tanks above the former Royal Navy base at Lyness in Hoy are the result of one of the greatest feats of engineering ever seen in the islands.
Now they could be brought back to use if an innovative new project is given the go ahead.
Arriving on the ferry at Lyness, evidence of Orkney’s wartime past is all around you. The fascinating Scapa Flow Visitor Centre and Museum and its old propellers, torpedoes and anti-aircraft guns greets you, with crumbling military buildings nearby and across the bay.
Up on Wee Fea hill, the remains of a former communications base loom large over the area. But look closer and you’ll also see the beginnings of something else, something much more significant.
An opening, cut halfway up the hill, leads to a locked gate. Standing there, peering into a pitch black tunnel, it’s hard to imagine quite what lies deeper inside. The concrete access tunnel is hundreds of metres long and it’s in incredible condition, testament to the men from around the world, including the UK, Ireland and Norway, that began building work in 1938, using a mixture of manual and explosive excavation.
For us, that gate was quickly opened, as we were lucky enough to be given a tour of the structure as part of an engineering inspection of access ladders, ahead of more in-depth studies to come. The first thing you notice as you pass through and head towards the heart of the hill is the strong smell of fuel oil. After Lyness closed as a naval base in 1957, the tanks were kept in civilian use for a further twenty years.
Looking back, the sharp circle of light marking the entrance to the tunnel becomes a distant dot, with just the echo of our footsteps filling the still, fume scented air. Eventually the tanks themselves are reached, encased behind thick concrete walls.
There are six in total, capable of holding more than 130 million litres of fuel. They were built into the hill for protection from air raids and supplied British and Allied warships stationed in the great harbour of Scapa Flow
They aren’t shaped like you’d imagine, though. They’re only nine metres wide, but most are 237m long, burrowed even deeper into the hill. The entire site, including access tunnels and the tanks, is effectively the size of the centre of Kirkwall. It’s hard to get your head around, isn’t it?
The location of each tank is marked by a tall ladder that leads to a viewing platform overlooking the tank itself. It’s these ladders, installed more than seventy years ago, that were being inspected during our visit.
Proposals to bring the tanks back into industrial use have been discussed in the past. They were sold to Orkney Islands Council in 1980 and a handful of potential developers have come and gone over the years.
Now the local authority has signed an agreement with Scapa Flow Asset Management Limited to provide access for initial feasibility studies, with the potential plan being to bring the tanks back into use as a storage and distribution base for low sulphur marine gas oil.
There is a long way to go though. They haven’t been used commercially for more than half a century, and despite the high quality of workmanship, they are still more than seven decades old. But initial investigations are positive. Coupled with the storage space and strategic location, right at the centre of Scapa Flow, they could be a perfectly placed asset.
Even if the tanks aren’t brought back to life as a commercial enterprise, there are already thoughts as to how this unique site could be used.
There is even a suggestion that they could be opened up so more people can take the long walk into Wee Fea hill, to marvel at the construction of one of Orkney’s most impressive, and secret, structures.
Find out more about the island of Hoy via our dedicated page.
If you're interested in seeing Lyness and Orkney's wartime heritage for yourself, find out how you can visit with the Visit Orkney website.
The Digital Media Orkney project is being part financed by the Scottish Government and the European Community Orkney LEADER 2014–2020 Programme.