
Loch Ness forms a substantial part of the Great Glen – a major topographical feature that divides the Highlands in an almost straight line from coast to coast. It’s a geologically complex area but the major landscape characteristics that we see from this boat today were fashioned principally by water erosion during the last 60 to 100 million years and also by recent glacial activity.
Loch Ness and the Great Glen owe their existence to a shattering fissure in the earth’s crust that occurred many millions of years ago; perhaps as far back as 380 million years ago.
Over the years there has been a lot of disagreement amongst geologists as to how this displacement actually took place. However over the years research undertaken by oil companies and universities has shown that the Great Glen Fault Line was the result of lateral movement or strike slip. The evidence that supports this theory includes the straightness of the fault, the shattered rocks on both sides and the similarity between the granite at Foyers on Loch Ness-side and Strontian near Fort William.
At the time of the original fracture Loch Ness would have been filled with broken stones, rather than water. However during numerous Ice Age periods, glaciers pushed these broken stones towards Inverness and the Loch was filled with water. Loch Ness is in fact a very large example of what is known as a ‘glacier trough’.
It is also believed, with good reason, that Loch Ness was once a salt water loch. However alluvial deposits of sand and gravel left by glaciers eventually blocked up the Inverness end of the loch and now Loch Ness is a fresh water loch.
Find out more about the surroundings of this fascinating area when you travel and tour with Jacobite Cruises.








Written records show that a castle has stood on this site from at least the 13th Century, as a result of an uprising by the people of Moray against King Alexander II. With the rebellion quashed, the King named his son-in-law, Alan Durward, the Lordship of Urquhart, and established a stronghold in the area.








