I embarked on a pilgrimage this summer to follow in the footsteps of Charles Rennie Mackintosh, Scotland's world-famous architect and designer, to where he spent the happiest days of his life.

No, not to the Glasgow School of Art, nor the Willow Tearooms, or The Herald building in Mitchell Street, now The Lighthouse, nor to the wonderful heritage of the furniture he designed, and the houses he created at Kilmacolm and Helensburgh.

Instead I drove more than 1000 miles to the very deep south of France, where Mackintosh spent the last four years of his life painting watercolours in the fishing villages of Collioure and Port Vendres.

Initially he and his artist wife Margaret - they met at the Glasgow Art School - took the long road there in the autumn of 1923 for a painting holiday to Roussillon as his architectural career floundered and her asthma worsened. Then they decided to stay in the Catalan area of the French Pyrenees-Orientales, for her health, his art, and their pocket.

The two beautiful ports are 15 miles from the Spanish border on the Mediterranean coast where the neat rows of vines literally cascade down the hills to the seashores. He wrote at the time: "We think it is one of the most wonderful places we have ever seen …This lovely rose-coloured land."

But Mackintosh was not the first artist to stay in Collioure. The climate and clear light, not to mention the lower cost of living, first attracted Henri Matisse - "No sky more blue than that!" - followed by Marc Chagall and Pablo Picasso among others.

As there was no hotel in 1924 -unbelievable now in this teeming tourist hotspot - they found lodgings in Fauborg, a Protestant quarter outside the old town walls: "We can live here for only 8/-d (eight shillings) a day, and that includes wine! It is lovely." Margaret wrote: "We like life here so much. Toshie is as happy as a sandboy - tremendously interested in his painting. Of course doing some remarkable work."

During one of his trips inland to fellow painter Frank Haviland he painted Fetges, which he described as the best he had done. It is now in the Tate Gallery, London.

His painting Collioure was one of the few exhibited during his lifetime, in Chicago in 1926, where it still is in a public collection.

But Mackintosh wanted to get away from the painters of Collioure to Port Vendres - the lesser known port and harbour three miles.

He and Margaret set up home in the Hotel du Commerce right on the harbourside and stayed there for two years, where he painted 13 watercolours which, along with others, are housed in Scotland and worldwide.

His hotel balcony looked out on to the busy working port below. You can still see the spot where he painted Steamer Moored At Quayside where he included figures for the first and only time.

But time was running out and he had to return to London for treatment for tongue and throat cancer and, in December 1928, he died, aged 60.

He had not signed some of his paintings and died with a pencil in his hand doing so. Just after, an invitation arrived asking him to be a guest of honour at a VIP dinner in Vienna to mark "his influence upon the art and architecture of his time".

His link with Port Vendres was to continue, however. True to his death-bed wishes, it is said Margaret made the long journey back and scattered his ashes in the harbour, the scene of many of his paintings. She returned every year until her death in 1933.

Today the Hotel du Commerce on Quai Pierre Fourgas is a ground-floor bank and the upstairs rooms are apartments - they stayed in a middle room on the middle floor. His lodgings in Collioure are unknown but the Fauborg quarter is now a busy tourist area with restaurants and bars such as The Templiers on the Quai de l'Amiraute. Mackintosh and his artist pals used to drink there and it has scores of paintings on the walls, mostly given by aspiring Picassos in exchange for drinks, food or lodgings.

Facing you across the bridged moat is the massive Royal Castle first built by the Knights Templars in 1207 which dominates the town, overlooking the beach. Legend has it that the crusading knights brought back the Holy Grail to the castle.

It is still used by the military, as a training base for France's special forces commandos.

Unlike their SAS counterparts, who do everything in utmost secrecy, here they strut around in public and practice in the bay as tourists film and they stage shoot-outs nearby within earshot. An interesting diversion.

But back to Mackintosh. Enthusiasts here, in conjunction with the Charles Rennie Mackintosh Society of Scotland, have devised an excellent trail, detailing the very spots where he sat - on his three-legged stool or simply a rock - painting his three pictures in Collioure and 13 in Port Vendres, three miles south towards the Spanish border.

At each spot is a copy of the painting so you can compare today's scene with his interpretation - though he did "cheat" slightly by omitting certain objects, and moving others into his view to improve the image.

There is also a first-class interpretation centre in Port Vendres in The Dome, the former military commander's residence, behind a magnificent high obelisk erected in the 18th century to praise King Louis XVI. The centre, staffed by kindly, helpful ladies, has a mass of information and a fascinating gallery of all of Mackintosh's French works.

Fine restaurants abound, some specialising in the Catalan Spanish-style food, and tapas bars. Apart from the smaller, gently sloping beach in Collioure, there are acres of long beaches within a few miles.

It is also a good base to drive inland to nearby Ceret, where Picasso and a host of others settled, and for visiting Figueres in northern Spain, where the entertaining Salvador Dali Museum is based.

It is truly a beautiful, picturesque spot and it is hardly any surprise those artists loved it. So did I ... mind you, it's a bit more than Toshie's 8/-d (eight shillings) a day.