Corrieshalloch is one of Britain’s most dramatic gorges. It clearly shows how glacial meltwater carved deep channels through solid rock. During the Quaternary ice ages, between 2.6 million and 11,500 years ago, meltwater followed natural faults in the bedrock across several glaciation periods.
A short, steep walk leads to a Victorian suspension bridge. From there, you can look down on a series of crashing waterfalls.
John Fowler, the pioneering engineer behind the world’s first underground railway and co-designer of the Forth Railway Bridge, built the suspension bridge. Corrieshalloch Gorge is a National Nature Reserve, recognised for its striking landscape and surrounding woodland. The mile-long canyon takes its name from the Gaelic for “ugly hollow”.
The project included a new National Trust for Scotland visitor centre with toilets and a coffee shop. The timber-framed building features a CLT deck and glulam beams supporting the roof and canopy over a decked area. Builders cast the foundations onto shallow rock, which they carefully broke out to meet level requirements on the sloping, narrow site.
A new car park serves the Corrieshalloch visitor centre. Narro designed it to be both practical and sympathetic to the natural surroundings. Due to limited space, we led discussions on how best to integrate the car park with the new path network. One result was a large hessian-bagged retaining wall at the entrance road. This separates road and path levels while preserving the area’s natural feel.
The main car park aisles use standard asphalt. However, we adjusted levels to drain into porous areas. Instead of traditional structures, we used innovative, environmentally sensitive retention methods that blend with the landscape.
We managed rainwater using SuDS, including porous parking surfaces and attenuation with filtration and flow controls. We diverted and reconnected short sections of disrupted overland flow to maintain natural drainage routes. Foul water flows into a piped system linked to an underground treatment plant. This discharges into the Abhainn Droma, following SEPA’s review and approval.
We also designed drainage for the building and car park. The shallow rock, steep gorge sides, and tight site made this particularly challenging.
Finally, we repurposed the existing car park by repairing potholes and repainting markings.
