Around 400 million years ago, the land masses of northern Scotland and the remainder of southern Britain collided and produced the Great Glen Fault. Today, this 100km long valley still divides Scotland in two. A clear line can be seen on a map running from Fort William in the west to Inverness in the east. The Great Glen Way follows the line of this valley and as a result, this is one of the easier long distance trails in the country. Water is the defining characteristic of the Great Glen with Loch Ness being the most famous of the bodies of water encountered en-route. The Caledonian Canal runs the full length of the Great Glen making use of the three lakes of Loch Lochy, Loch Oich and Loch Ness as it makes its way from the west coast to the east coast of Scotland.

It is better to begin at Fort William rather than Inverness; the easier sections are here and it keeps any prevailing weather behind you. From the fort that gives the town its name the trail makes its way through the outskirts to the start of the Caledonian Canal at Corpach where it turns north-east to the set of canal locks at Neptune's Staircase and the beginning of the trail proper. A gentle introduction follows, along the flat canal towpath through woodland and past the ruins of Tor Castle by the River Lochy to the start of Loch Lochy. Here, boaters enjoy a change as the canal opens into the lake via a set of lock gates. The walking trail also changes in character here as it takes to forestry tracks along the side of the loch, offering stunning views across the lake to the southeast. At the top end of Loch Lochy, Laggan Locks open into a second stretch of canal. This is the highest point on the canal as this area marks the watershed between the River Lochy to the south-west and the River Ness to the northeast. The trees along this section of the towpath are magnificent.
As the canal open up into the loch at the Laggan swing bridge, we join General Wade's Military Road through scattered mixed woodland along the beautiful southern shore of Loch Oich. The next section is along the Caledonian Canal once more and is sandwiched between the canal and the River Oich.