Welcome to Knockan Crag National Nature Reserve
Step on three billion years of history, bridge 500 million years with your bare hands and dig into deep time. The landscape around Knockan Crag reveals some of the world’s oldest rocks as well as evidence of the huge upheavals, collisions and pressures that have shaped the land we call Scotland. You can see the clue that allowed one of the world’s greatest geological mysteries to be solved.
Travel into deep time
At Knockan Crag you view a landscape so old that it is almost impossible to imagine. Think of the history of the planet as a 24 hour clock. Modern humans first inhabited it at 23:59:59, just one second in deep time.
The crags and glittering pools known as ‘cnoc and lochan’ expose some of the world’s oldest rocks. Bog and heather overlie seabed muds, a billion years old. The bedrock of the mountains is sediment dumped by ancient rivers while the whitish rocks on some summits were formed from sand in tropical seas when Scotland lay south of the Equator. Over millions of years, ice, weather and erosion have shaped the rocks into the landscape you experience today.
Up close and puzzling
At the Puzzle Wall layers of rock reveal one of Earth’s great upheavals. The bottom layers show traces of marine creatures which lived beside tropical seas. Above is a layer of lime rich mud. On top is the puzzling layer, laid down nearly half a billion years earlier, when Scotland was part of the same continent as North America. The closing of a huge ocean led to the collision of two continents and the birth of the landmass that is present-day Britain. The force of the collision thrust up these older rocks to make them top of the pile.
Reading the riddle of the rocks
After years of debate, two brilliant geologists solved the puzzle of how older rocks can lie on top of younger rocks. By mapping the folds, thrusts and contours of the landscape here in 1882, they discovered that Earth’s enormous forces could move rocks sideways. The older rocks had been pushed up and over younger rocks in a process called thrust. At the Rock Room, you can meet those remarkable geologists, Peach and Horne, discover how continents collided and try out your skills as a rock detective.
Find out more
- Support this NNR at nature.scot/donate-nnr
- Follow @ ScotlandsNNRs on social media
- For more information please contact 01463 701600 or email [email protected]
Walk back into deep time
From the Rock Room three trails take you to the features that make Knockan Crag special. The Crag Top Trail rewards you with an eagle’s eye view of deep time on this circular route with a few steep climbs past the Moine Thrust. About one hour.
The Thrust Trail takes you to the spot where Peach and Horne solved the mystery. 30 minutes. The Quarry Trail is an easier option avoiding the climb to the Thrust. 20 minutes.
An inspiring landscape
On the trails you will discover how artists and poets have interpreted this ancient landscape.
‘Something to do with time has all to do.
With shape and size …’
Stop, look and listen
You may meet other visitors on the trails. In summer, song thrush, stonechat and meadow pipit serenade walkers and ravens and nesting kestrels haunt the cliffs. Frogs shelter in damp hollows and lizards sunbathe close to the paths while eagles and buzzards circle the mountains.