The Creature, the Castle and the Canal by Bruce Holmes

In 1916 James Cameron walked into his local hotel, his face ashen-white and barely able to speak of what he had seen. In 1933 Mrs Aldie Mackay, the manageress of the Drumnadrochit Hotel, was driving on the road from Inverness when she saw something resembling a whale, a sighting she tried not to publicize.

Under darkening skies the modern day visitor peers at the waters of Loch Ness, even now intrigued by the legend of the monster.

The northern shore of Loch Ness was impassable because of steep cliffs until it was opened up in 1932 with the blasting of the rock and subsequent building of the A82 road, which meant a much greater influx of visitors. Little wonder then that 1933 became the year of the monster with sightings galore.

Today visitors can hear about what people saw, or thought they saw, at The Official Loch Ness Exhibition Center where an intriguing audio-visual display tells the history of the Nessie sightings, of which there have been a thousand, and those hoax photographs that made headlines around the world.

Who hasn't seen the photograph of the dinosaur-like creature with its long neck out of the water, which the surgeon Kenneth Wilson claimed to have taken in 1934?

Stretching 39km (24 miles) from near Inverness to Fort Augustus the famous loch holds the greatest volume of water of any of the Scottish lochs. Plenty of room for a monster to hide in, it would seem.

And so the investigations and expeditions began in earnest. The presentation shows how these were conducted, using original footage and photographs from the Loch Ness Project Archive and displaying equipment from various monster hunts.

I was particularly intrigued by the fact that a 1982 project used Scanning Sonar to map the lake and found 40 mystery contacts, red echoes much larger than the largest fish. And yet when the fleet spanned the entire width of the lake in 1987 to re-check those contacts it found all but three were fixed objects. Oh, and those other three?

They had disappeared!

The exhibition, designed and written by researcher Adrian Shine, has played host to 230,000 visitors in a year, 42% of them from England. It evokes a definite atmosphere, and as the commentary ends it is left "for you to judge whether the waters are a veil that will one day be lifted or a mirror to our own imagination."

Driving away from the center, remember to watch the road and not the lake.

Heading south it's not far to Urquhart Castle from which the views of the loch are spell-binding. The castle has been here since the 12th century and prior to that there was a prehistoric hill fortification on this strategic site.

It may have been the stronghold of Brude, King of the Picts when Saint Columba visited here in 565AD, the missionary making the sign of the cross to banish the monster (or Aquatalis Bestia as he called it) and prevent it from devouring one of his followers.

The demolished remains of the gatehouse are strewn about, blown up in 1692 to prevent the rebellious Jacobites from using the fortress. Fought over so often, it is hard to imagine that in peacetime after the Tower House was built in the 1500's there would have been music, the bustle of guests and the regular collection of taxes.

Seeing this castle you'll think it's déjà vu but no, you really have seen it before. This has to be one of the most photographed ruined castles in all of Britain, especially its Tower House and Nether Bailey.

Pausing to take in the view from the top, you look out at the darkening Loch Ness and search for signs of what might be.

Leaving the castle, there is yet one more impressive construction feat of which Loch Ness forms a part.

This is the Caledonian Canal, designed and constructed by one of the Industrial Revolution's greatest engineers, Thomas Telford between 1803 and 1822 at a cost of more than £900,000.

The canal links the Atlantic Ocean with the North Sea through a series of locks which can raise or lower a vessel to the level of the next natural loch. The waterway is 96km (60 miles) long of which distance two thirds is made up by Lochs Linnhe, Eil, Lochy, Oich and Ness. Superseded by 20th century shipping, it now caters only for fishing boats, yachts and small cruisers.

Reaching Fort Augustus at the end of Loch Ness, you think of your journey past that deep and dark expanse of water, and wonder whether there's a monster lurking within it.

But the sheep grazing at the southernmost point show no sign of nerves at all, as if almost nonchalantly they might say, "Ah tourists! What vivid imaginations they have."