On April 14, 1933, a Mr. and Mrs. John MacKay were driving toward their home on the edge of Loch Ness in Scotland when they were astonished to see a large, strange creature slicing through the water. A few days later, they mentioned it to a friend who was a correspondent for the Inverness Courier. He wrote an account for his newspaper about the Loch Ness monster, as he dubbed it, and the tale was quickly picked up by newspapers all over the world. Thus began one of the century's greatest mysteries/hoaxes/publicity stunts, depending on how you choose to look at it.

Today, more than half a century later, hundreds of thousands of people a year continue to travel to the loch in hopes of glimpsing the elusive creature (for the record, there have been more than 3,000 reported sightings), and in the process have made Loch Ness one of the best known and most visited small bodies of water in the world.

It is a handsome lake, and, considering its fame, it remains remarkably unspoiled. One or two lochside villages, notably Drumnadrochit, are unashamedly touristy, with lots of garish post cards and dubious-looking souvenirs on display. But elsewhere throughout its 23-mile length, Loch Ness offers an agreeable and surprisingly unsullied panorama of water, hills and compact farms.

No one knows just how many lochs there are in Scotland, but most estimates put the number at several hundred. They come in two types: freshwater lochs, like Ness, which are simply what the rest of us call lakes; and sea lochs, which are fjord-like inlets fed by mountain streams at one end and which open to the sea at the other.

Most lochs cover the narrow floors of mountain valleys, and thus tend to be long and thin -- typically about 20 miles from end to end and no more than a mile or two across -- and perilously deep. Loch Ness, for example, is 900 feet deep in places.

Set against a backdrop of echoing glens, tumbling streams and steep hills, most lochs are deeply, sometimes inexpressibly beautiful. The beauty is lent additional depth and intensity by the constantly shifting weather. Scotland may be the only place in the world where you can experience all four seasons between lunch and dinner. There are few experiences more beguiling than to watch a dull landscape of gray skies and leaden water instantly transformed into something sparkling and bright as the sun emerges from a blanket of clouds, turning the hills a deep green and the waters a translucent blue -- like a television that has been switched from black and white to color.

At some lochs, where beech and birch woods creep down to the water's edge, and the odd fisherman's rowboat rests on the water, the atmosphere is intimate and pond-like. At others, where the mountains part to reveal a vista of sea straits and distant hazy islands, the effect is far more spectacular, particularly at sunset, when the skies are streaked with pink and the black waters shimmer with the reflections of mountains. The roads around many of the lochs, and indeed throughout much of the Highlands of Scotland, are often sinuous and narrow (though mercifully free of traffic). For the lone driver it is a constant struggle to take in the hypnotic scenery without overshooting a hairpin bend and sailing glider-like off into some spectacularly pretty void.

After Ness, the most famous loch is Loch Lomond, immortalized in that anonymous song to which everyone knows the beginning ("O you take the high road and I'll take the low road") and the finish ("On the bonnie, bonnie banks of Loch Lomond") and not a word in between. Often called the queen of the lochs, Loch Lomond is the largest lake in Britain. Twenty-four miles long and shaped roughly like a stocking, it is broad and dotted with wooded islands and sailing boats at its southern end, but tapers to a half-mile-wide channel where the mountains crowd in to the north. The little lochside village of Luss, with its snug cottages, tidy beach and 19th-century church, is entrancing. But the loch is perhaps best viewed from the passenger boat Countess Fiona, which cruises throughout the summer between Lomond's four villages. A trip from one end of the loch to the other takes about two hours, and it calls at places on the eastern shore that are otherwise inaccessible.

The one notable shortcoming of Loch Lomond is that it tends to get crowded due to its proximity to Glasgow, just 15 miles to the south. More than a million people -- about a fifth of the entire Scottish populace -- live within a 30-mile radius of the loch, and on a Sunday afternoon in high summer it can seem as if they have all gone there.

Most of Scotland's lochs are in the western half of the country, and several of the most scenic and appealing are conveniently clustered in a relatively compact area around the port of Oban, about 85 miles north of Glasgow on the west coast. These include Lochs Awe, Etive and Leven and the wider, more majestic sea lochs of Loch Linnhe (pronounced "Linny"), Loch Long and Loch Fyne. All are gratifyingly unspoiled. In fact, considering the importance of tourism to the country, much of Scotland still leaves you with the happy sense that you are something of a welcome rarity.

A small train line runs between Glasgow and Oban, giving tantalizing glimpses of some of the lochs en route. In fact, you could get off at the hamlet of Lochawe, on Loch Awe, and have a look around. But really, the only realistic way to tour this part of the world is by car. Towns and other amenities are few and far between.

Loch Awe, for instance, is more than 50 miles around, but it has just four hamlets along its banks, and most of those consist of no more than a couple of houses and a tiny post office/general store. You can easily find yourself 10 miles from the nearest guesthouse, which is no great problem if you have a car, but more than a little daunting if it's 9 o'clock at night and you are on foot.

Having said that, however, I must add that virtually every glen, or valley, in Scotland has at least one good hotel, almost always with a restaurant and bar, and in summer most homes in the Highlands hang out bed-and-breakfast signs.

Oban (pop. 8,000) and Fort William (pop. 11,000), about 50 miles to the north, are the only towns of any size. Both are fairly workaday communities, though Oban has a notable folly overlooking its harbor. Called McCaig's Tower and modeled on the Colosseum in Rome, it was conceived as a Scottish hall of fame by a local benefactor in the 19th century, but was never completed. Now it is a ruin, but still offers magnificent views over Loch Linnhe and the Firth of Lorn to the nearby island of Mull.

The western half of Scotland is awash with history, much of it bloody. The wild and rugged valley of Glen Coe a few miles inland from Loch Etive, was the scene of a notorious massacre, when the Campbell clan ruthlessly slaughtered the sleeping MacDonalds -- men, women and children -- after entertaining them as guests for two weeks in 1692. The National Trust for Scotland has a visitors' center in the heart of the glen providing a slide show on the history of the massacre.

The Campbells' principal seat, Kilchurn Castle, is now an imposing ruin in a glorious setting on the edge of Loch Awe. It is a half-mile hike from the nearest road and hardly anyone goes there, so you may find, as I did, that you have it all to yourself. The Campbells, who eventually became the Dukes of Argyll, later moved their main base to Inveraray, a strikingly pretty town of white houses on the banks of Loch Fyne. The castle they built there in the 17th century still stands and is open to the public.

The dominant historical figure of western Scotland, however, was Prince Charles Edward (better known as Bonnie Prince Charlie), grandson of King James II and pretender to the throne. In 1745 he landed in Scotland with just seven men and began a long march that took him from Glenfinnan, near Loch Linnhe, deep into the heart of England, where he nearly ousted King George II.

The upstart prince was finally vanquished at the Battle of Culloden, near the head of Loch Ness. It was the last battle ever fought on British soil., and it marked the end of the clan system in Scotland.

The National Trust for Scotland operates visitors' centers at both Glenfinnan (where there is also a much-visited monument to the prince) and at Culloden, where the battlefield has been preserved. Both provide audiovisual shows that explain the history of the Scottish rebellion. The nearby house that Bonnie Prince Charlie used as his headquarters before the Battle of Culloden is now an elegant country house hotel.

Slightly farther afield, but well worth seeking out, is Loch Tay, Queen Victoria's favorite loch, about 40 miles east of Oban. For my money, the drive along its southern side, from the attractive village of Kenmore through Acharn and Ardeonaig, is the loveliest in Scotland. The narrow road sits high above the loch, inside a tunnel of trees, and provides views across the placid waters to the distant, smoky mountains of Glen Lochay that are simply stupendous. The person who has seen Loch Tay on a fine day has glimpsed heaven.

Bill Bryson, author of "The Palace Under the Alps," is an editor for the Independent in London.

WAYS & MEANS

GETTING THERE:

Glasgow, a good point to begin a tour of the lochs, is 400 miles north of London. Trains run every 90 minutes throughout the day from Euston Station in London. The trip takes 5 1/2 hours. The basic round-trip second-class fare is

38 (about $60). Alternatively, British Airways offers an hourly shuttle service to Glasgow from Heathrow. The flight takes one hour and costs

74 ($121) round trip, if purchased two weeks in advance.

GETTING AROUND:

The main car rental companies have pick-up points at the Glasgow airport and in the downtown area. A typical rental fee for a small car from Budget Rent-a-Car is $122 a week, plus tax and about $10 a day for insurance, with unlimited mileage. You must have a valid American driver's license and be between the ages of 23 and 65.

If the idea of driving on the wrong side of the road is too much to bear, Midland-Scottish Buses, Goosecroft Road, Stirling, and Glendochart Coaches, Killin, Perthshire, both offer organized bus tours, and Go Where You Please Tours, at 1 Easewald Bank, Kilbarchan, Renfrewshire, provides chauffeur-driven tours for

90 (about $150) a day.

WHERE TO STAY:

Although finding a place to stay is seldom a great problem, it is a good idea to book accommodations in advance during the summer high season. Guesthouse prices start at about $10 a person for bed and breakfast. If you want slightly higher standards -- a room with its own bath and color television, for instance -- you'll have to find a hotel. Typical hotels in the Highlands are the Onich Hotel, on the banks of Loch Linnhe, and the Brander Lodge Hotel, near Loch Awe. Rates at both start at about $30 a person and include breakfast.

The Scottish Tourist Board's "Where to Stay" guides, available through the British Travel Bookshop, 40 W. 57th St., New York, N.Y. 10019, (212) 765-0898, have comprehensive listings of hotels and bed-and-breakfasts in Scotland. They cost $7.95 (hotels) and $5.75 (bed-and-breakfasts); add $2.50 for shipping for each volume.

INFORMATION:

For additional information: Highlands and Islands Development Board, Bridge House, 27 Bank St., Inverness IV1 1QR. Scottish Tourist Information Center, 19 Cockspur Street, London. British Tourist Authority, 40 W. 57th St., New York, N.Y. 10019, (212) 581-4700.